National Weather Service United States Department of Commerce

Monsoon Awareness Week is June 9-15, 2024

Summer in the Southwest

Each year, a variety of weather related dangers affect the American Southwest, especially from late spring into early autumn. Through a collaborative effort between SW U.S. National Weather Service offices, the time period from June 15th through September 30th has been defined as "The Monsoon." A period of extreme heat is typically ongoing at its onset, which in the coming days or weeks is followed by an influx of moisture leading to daily rounds of thunderstorms. The heat is deadly in its own right, causing more deaths than any other weather hazard in the region each year. In addition, thunderstorms present an array of hazards which often strike suddenly and with violent force.

Lightning strikes, high winds, dust storms, wildfires, tornadoes, flash flooding and extreme heat cause numerous deaths and injuries along with tens of millions of dollars of damage each year (see  Road closures, as well as power and communication outages are additional consequences of monsoon weather hazards.

Every June, SW U.S. NWS offices work with public safety partners and broadcast media to observe Monsoon Awareness Week with the goal of reducing the number of deaths, injuries and property damage caused by weather related dangers that occur during the monsoon. Through education about proper precautionary actions to be taken, lives can be saved and property losses can be minimized.

Warning Information for Monsoon Season

Armed with Doppler radars, powerful supercomputers, advanced weather satellites, automated weather and stream gages, and an advanced lightning detection network, forecasters at the National Weather Service are able to provide highly accurate severe weather warnings.

Advanced National Weather Service computer systems now allow warnings to be generated in seconds for highly detailed areas. Those warnings are then transmitted to the public, the media and emergency management officials via NOAA Weather Radio, the Emergency Alert System, and the Internet.

Television meteorologists play critical roles in the warning process. They relay National Weather Service warnings to the public and provide additional detail about the storms, what they are doing and where they are going. 

Weather Terminology — Understanding Watches, Warnings, and Advisories

  • A watch means that potentially life threatening weather or flooding is possible, or may occur in a matter of hours. Pay close attention to the weather, and tune into TV, radio, or NOAA Weather Radio broadcasts frequently.
  • Warnings (Severe Thunderstorm, Flash Flood, Dust Storm, or in rare cases, Tornado) mean that life-threatening weather is about to occur, or has been reported. Take action immediately.
  • Flood Advisories mean heavy rains will cause minor flooding of washes, streams, and typical flood-prone areas. Flooding in this situation is usually not serious. If the flooding does become life threatening, then the flood advisory is upgraded to a Flash Flood Warning.

Warnings are not issued for lightning, mainly because most thunderstorms, no matter how weak, produce deadly cloud-to-ground lightning.

Here is a summary of the severe weather watches, warnings and advisories the National Weather Service issues during the monsoon:
Severe Thunderstorm Watch: Conditions are favorable for widespread thunderstorms with damaging winds and even large hail to develop. These are usually issued only when an especially active day is expected. Watch weather reports and conditions closely.
Severe Thunderstorm Warning: A thunderstorm with damaging winds of 60 mph or greater is about to occur, or is already underway. These winds could also produce a dust storm with visibilities below ¼ mile. Hail over 1" in diameter or larger is also possible. Take cover now! Note that heavy rain doesn't always accompany a severe thunderstorm.
Dust Storm Warning: A dust storm, with visibilities of ¼ mile or less, is about to strike, or has already developed. Pull off the road now! Wind gusts between 40 and 60 mph are also likely. If winds associated with a dust storm are 60 mph or greater, then a Severe Thunderstorm Warning is also issued.
Tornado Warning: A tornado has been sited and is still on the ground, or is about to develop based on radar information. Take cover now!
Flash Flood Watch: Conditions are favorable for flash flooding over large or multiple areas of the region. These are usually issued only when an especially active day is expected. Monitor weather reports and conditions closely.
Flash Flood Warning: Life-threatening, rapid flooding is about to occur, or is already underway. Move to higher ground now! It is particularly dangerous to be in a low lying area or near a wash.

Weather Statistics

  • Tucson, Phoenix, Albuquerque, and El Paso average 5.69, 2.43, 4.48, and 5.27 inches of precipitation respectively during the Monsoon. A plethora of rainfall statistics can be found at the NWS Monsoon Tracker page.
  • On average, over 1.5 million lightning strikes occur in Arizona and New Mexico each year. This accounts for over 15% of all lightning strikes in the lower 48 states. See the National Weather Service lightning safety page for additional lightning statistics.
  • The highest risk of tornadoes is in eastern New Mexico during April through July, but tornadoes have been verified in most New Mexico counties. New Mexico averages about 10 tornadoes in a year. Even though Arizona rarely experiences a tornado, they do occur (an average of four every year). However, thunderstorm-generated winds can exceed 100 mph over a fairly large area, with the damage looking very much like tornado damage.


Although the monsoon brings welcome rains and relief from the summer heat, the thunderstorms that come with the
monsoon bring their own hazards. In fact, this is the most dangerous time of year weather-wise in Arizona. 

Click here for printable weather safety brochures


Planning ahead

The best way to avoid lightning, flash floods, and other dangerous conditions is by not being in danger in the first place. Many ways are available to gain weather information including:

  • Watching current weather forecasts on TV or the internet
  • Listening to weather reports on the radio or a NOAA weather radio
  • Subscribing to lightning and severe weather notification services
  • Scanning the skies 360 degrees around and overhead before leaving a safe location

Disaster Supply Kit Contents

Every family should prepare a family disaster supply kit in the event of severe weather conditions. The disaster supply kit should contain essential items such as food, water, and sturdy clothing, to sustain a family for up to three days since electric power, gas and water services may be interrupted.

  • Three gallons of water in clean, closed containers for each person and pet
  • First aid kit
  • A stock of food that requires no cooking or refrigeration. Canned food and a hand can opener
  • A NOAA Weather/All Hazards radio, and/or a battery-operated commercial radio, flashlights, and extra batteries
    (Candles and oil lamps are fire hazards)
  • Necessary medications
  • Special items like diapers, baby formula, prescription and essential medications, extra eyeglasses or hearing aids, and pet supplies.
  • Back-up power source for life support or other medical equipment that requires electricity to function
  • Extra clothing and bedding
  • An extra set of car keys
  • Credit card or cash

Flash Flood Safety

  • Flash floods are common in Arizona. There are thousands of low water crossing and dips which flood every summer. Know where they are, and avoid them during heavy rains.

  • Never ever drive into a flooded roadway. The water depth is very easy to misjudge, and the road itself may be damaged or destroyed underneath. It only takes about 1 to 2 feet of water to float most vehicles, including SUVs.

  • Never drive around barricades. They are there for a reason - usually because flash flooding is about to take place, is already happening or the road is damaged by flooding and is unsafe.

  • Never allow children to play near washes or storm drains after any rainfall, no matter how light. These flood easily and rapidly, and storm drains are usually so large that children can be swept away.

  • Beware of distant thunderstorms, especially if they're over mountains. Flash flooding can occur many miles away from the thunderstorm as the runoff flows into the valleys and deserts.

  • Do not camp overnight near streams during the monsoon. Although many of our thunderstorms occur during the afternoon and evening, some of our worst flash floods have occurred in the middle of the night.

  • Hikers and mountain bikers should try to get out earlier in the day to avoid the dangers of not only flash flooding, but also lightning. Wherever you are hiking during the monsoon, be aware of your escape routes, follow ranger instructions, and be prepared to move to higher ground quickly.

    Flash Flood Safety for Homeowners

  • If you live in a flood prone area have an evacuation plan.
  • Store materials like sandbags, plywood, plastic sheeting and lumber for protection from floodwaters and to make quick repairs after a severe storm.
  • Store materials above flood levels.
  • Secure wanted objects to prevent them from floating away.
  • Learn where to find high ground, which is safe from flooding. In a flash flood seek high ground quickly.
  • Contact an insurance agent to discuss flood insurance coverage. Flood losses are not covered under normal homeowners' insurance policies. Flood insurance is available through the National Flood Insurance Program. Get coverage early-there can be a waiting period before it takes effect.

Picture of a car caught in a low water crossing due to flash flooding from a summer thunderstorm.

Many governmental agencies are dedicated to alerting the community to road closures during our thunderstorm season. City of Tucson's Operation Splash and Pima County Department of Transportation pre-deploy barricades and emergency flashers to locations where they know water will be running across roadways, causing major problems for motorists.

Local law enforcement and fire departments pre-deploy response teams into areas that are known to become inaccessible during heavy rain and runoff conditions.

More deaths each year occur due to flooding than from any other thunderstorm-related hazard because people underestimate the force and power of water. Many of the deaths occur in automobiles that are swept downstream.

Turn Around Don't Drown™ Safety Tips

  • Driving around barricades is illegal and dangerous.
  • Do not let children play near storm drains or washes after a heavy rain.
  • Avoid low-water crossings.
  • Avoid camping in a wash or in the bottom of a canyon with steep side slopes.
  • Be especially cautious at night. Flood dangers are much more difficult to see in the dark.
  • Even a less serious urban flood can be dangerous. Driving too fast through standing water can cause a car to hydroplane. The best defense is to slow down or pull well off the road (with the lights off) for a few minutes to wait out heavy rains.
  • Avoid areas already flooded, especially if the water is flowing fast.
  • Do not attempt to cross flowing streams.
  • Do not camp or park a vehicle along streams and washes, particularly during threatening conditions.
  • If flooding occurs, get to higher ground. Get out of areas subject to flooding. This includes dips, low spots, canyons, washes, etc.
  • Roadbeds may be washed out under floodwaters. Never drive through flooded roadways.
  • If your vehicle is suddenly caught in rising water, leave it immediately and seek higher ground.
  • If a traffic signal is out, treat the intersection as a 4-way stop.
  • As little as ten inches of water can float average-sized cars, mini-vans, SUVs and trucks. Strength of the flow is the critical force.
  • When in doubt, wait it out, or find a safer route.

Lightning Safety

When thunder roars, go indoors! 

  • If you can hear thunder, you are close enough to be struck by lightning. There is no place outside that is safe from a lightning strike. The safest locations are large substantial buildings and fully enclosed metal-topped vehicles. Remaining indoors for 30 minutes AFTER the last rumble of thunder is heard,

When you see a flash, dash inside!

If fewer than 30 seconds elapse between the time you see a flash and hear the thunder, then the flash is less than 6 miles away. Research has shown that the most successive flashes are within 6 miles, which means that you should have reached a safe place if lightning is less than 6 miles away. However, lightning may strike up to 10 miles away from the parent storm.

If someone is struck by lightning, call 911 immediately.

Lightning picture

Outdoor Safety

  • Get away from open areas, including armadas, porches, trees, convertible cars, swimming pools, and open areas.
  • Plan outdoor activities to avoid being outside between mid afternoon and mid evening, especially in higher elevations where lightning is more common.
  • Remember that it does not have to be raining for you to be struck by lightning.
  • Bring pets indoors. Lightning and thunder are very scary for pets, and they are likely to panic or even run away to try and escape the storm

Indoor Safety

  • Never touch wiring during a thunderstorm. It's too late to unplug electronics if thunder is heard.
  • Corded phones are dangerous during thunderstorms. Lightning traveling through telephone wires has killed people. Cell phone and cordless phones are safe.
  • Wait to use any plumbing-sinks, showers, tubs, and toilets. Plumbing can conduct electricity from lightning strikes from outside.
  • Unplug expensive electronics including TV, stereo, home entertainment centers, and computers when thunderstorms are expected, and before the storm arrives. Typically, summer thunderstorms form in the early to mid-afternoon, when most people are at work.


Power and Communications Outage Safety

Power and communications outages can be more widespread and last longer than a thunderstorm. Be ready for outages inside and outdoors by taking precautions and actions to minimize inconvenience and maximize safety. Protect sensitive electrical equipment by installing power protection devices that can be purchased at department, hardware or electronics stores.

Indoor Safety

  • Stay at home.
  • Use a cell phone. Cordless phones do not work without electricity. Use corded phone only for emergencies.
  • Unplug sensitive electronic equipment before the storm arrives.
  • Turn off electric appliances that were on before power was lost. Leave one light on as an indicator for when power is restored.
  • Keep refrigerator and freezer doors closed — food will stay fresh up to 8 hours.
  • If the power is out for less than two hours, do not open the refrigerator or freezer. This will help food to stay cold. For a power outage lasting longer than two hours, pack cold and frozen foods into coolers. As a general rule, perishable foods should not be held over 40 degrees for more than two hours.
  • During a thunderstorm, turn off the AC unit. Power surges from lightning can overload units, leading to costly repair bills.

Outdoor Safety

  • Stay away from downed power lines.
  • Call 911 to report downed power lines.
  • If a power line comes into contact with your vehicle, remain inside the vehicle until help arrives. Do not attempt to get out of the vehicle - that is the safest place for you to be. By stepping out of the vehicle, your body can become the pathway for electricity to reach the ground, causing severe bodily harm and possibly electrocution. Use a cell phone, if available, to notify emergency services of the exact location.

How Storms Affect the Delivery of Electric Power

  • Power companies often plan for storms in advance, ensuring that their equipment is working, keeping a sufficient amount of supplies on hand and placing extra crews on call. TEP's computer-operated Outage Management System allows service to be restored as quickly and as safely as possible.
  • High winds and lightning strikes can cause lines to cross and short out or break, thereby interrupting the flow of electricity.
  • Lightning can strike a transformer on a pole or a substation interrupting the delivery of electricity — even miles away from the location of the strike.
  • TEP is continuously servicing and upgrading our equipment, making it more able to withstand storm hazards.

Thunderstorm Winds

  • Thunderstorms frequently produce strong downward rushes of air, called downbursts or microbursts.
  • Thunderstorm wind gusts in Arizona almost always exceed 40 mph. The strongest straight line wind gusts can exceed 100 mph, and can produce damage as severe as a tornado! Anytime a thunderstorm approaches, no matter how weak it seems, move indoors to avoid flying debris. Winds rushing down from a thunderstorm can develop very quickly.
  • When a Severe Thunderstorm Warning is in effect, it means damaging wind gusts of 60mph or higher are likely. Move into a central interior room. Stay away from windows.
  • Unanchored mobile homes are NOT safe in any severe thunderstorms, and even anchored mobile homes can be heavily damaged in winds over 80 mph. Move to a more sturdy structure.
  • Stay away from trees. The vast majority of people are killed or injured in severe thunderstorms by trees falling on them, from flying debris, or from downed power lines.
  • Never touch a downed power line, even if it appears dead. Assume that it is live. Call for help instead.
  • Straight line winds can travel dozens of miles away from the thunderstorm that produced them. If the wind suddenly shifts and blows toward you from an approaching storm, while the temperature either becomes much colder or much hotter, the winds are likely to become even stronger. Move indoors!
  • Secure outdoor furniture and garbage cans, or move them indoors. These are frequently blown around by thunderstorm winds.
  • Close garage doors to prevent inward rushing air from removing the roof or downing walls. 

Picture of down power lines/poles in Tucson.

Dust Storms

  • These are an underrated killer in Arizona! Straight lines winds in any thunderstorm can lift huge clouds of dust and reduce visibilities to near zero in seconds, which can quickly result in deadly, multi-vehicle accidents on roadways.
  • Dust storms, or haboobs, are more common during the early part of the monsoon, but can occur at any time during the season, depending on rainfall patterns. Be prepared for blowing dust and reduced visibilities any time thunderstorms are nearby.
  • Remember: PULL ASIDE, STAY ALIVE! If you encounter a dust storm, and cannot avoid driving into it. Pull off the road as far as you can safely do so. Turn off your headlights and taillights. Put your vehicle in "PARK," and/or engage your parking brake, and take your foot off the brake (so your brake lights are not illuminated.) Other motorists may tend to follow tail lights in an attempt to get through the dust storm, and may strike your vehicle from behind. For additional information, see
  • Dust storms usually last a few minutes, and up to an hour at most. Stay where you are until the dust storm passes.

Picture of a dust storm from a car. Picture of a big dust storm otherwise known as a Haboob.


Tornadoes do occur in Arizona--on average about 4 each year. Most tornadoes develop from the ground up when a dust devil is drawn upward by thunderstorm updrafts. When contact is made with the cloud base, a "landspout" tornado is formed. While they do not last long, they can occur with very little advanced notice, and can do considerable damage. If you see a tornado, take the same precautions you would for a severe thunderstorm. Move inside a strong building away from windows. A small, central, interior room like a bathroom is best.

Picture copy of a news headline from the Arizona Daily Star which highlighted a tornado that hit southwest of Tucson.


Large hail is defined as being greater than 1" in diameter. Hail the size of golf balls may occur, but is more common in the mountains and mid elevations. If possible, move your vehicle to a carport or garage to protect them from hail damage, but do so well ahead of time. But do not put your life at risk! Lightning and straight line winds are far more dangerous than hail. 

Small hail driven by powerful thunderstorm winds can also cause damage.  Sometimes substantial amounts of small hail can also cause hazardous road conditions.

Picture of hail covering the ground in Cananea Sonora Mexico.

Extreme Heat

Although the monsoon is generally associated with slightly cooler temperatures and rainfall, excessive heat is still by far the number-one, weather-related killer in Arizona. Unfortunately, many heat-related deaths occur during the monsoon as our typical summertime heat is combined with increased monsoon humidity. Here are some heat safety tips to keep in mind throughout the summer:
  • Drink plenty of water. It is very easy to become dehydrated in our desert climate without realizing it.
  • Avoid alcoholic or caffeinated beverages. Both increase stress on the body and actually accelerate dehydration.
  • Wear light, loose-fitting clothing.
  • Stay out of the sun as much as possible.
  • Shift strenuous outdoor activities too cooler parts of the day, especially during the early morning.
  • Check on elderly friends, neighbors and family often. Elders are generally more susceptible to heat-related illness.
  • Take advantage of air conditioning when possible. Many homes in southern Arizona still use evaporative cooling (swamp coolers) which are much less effective during the monsoon.
  • If you, or someone you're with, begins to feel tired and flushed and begin to sweat excessively, you may be suffering from heat exhaustion. Stop any strenuous activities immediately, drink more water, and find a cool place to rest.
  • If someone becomes disoriented, stops sweating, has hot dry skin, or even worse, passes out, that person is probably experiencing heat stroke - a serious medical condition. Call 911 immediately! If possible, move them to a cooler location.
  • Provide plenty of water and shade for pets.

Thunderstorms and Your Insurance Policies

The following topics are all important and should be discussed with your personal insurance agent at least every few years. Hundreds of thousands of people each year are impacted by thunderstorms. Unfortunately, too many of them are surprised when they try to make a claim on their insurance only to find out they had no protection for certain losses under their policies. A bad thunderstorm should only ruin your day, not your life. Not having the right protection at the wrong time can be financially devastating.

How to Minimize Your Storm Related Losses

  • Find a local insurance agent who you trust and that will listen to your concerns
  • Only work with an agent or their licensed staff members
  • Make sure your home is protected to the proper amount
  • A homeowner's policy won't protect an automobile for any reason - hail, flood damage or other weather related losses to a vehicle are only covered by Comprehensive coverage on your automobile insurance policy
  • Water from the sky is usually covered under a homeowner's policy - once it hits the ground it's usually covered only by a flood policy
  • Trees can fall on houses in a storm. Damage to the home is usually covered - does you policy provide for removing the fallen tree or replacing it with a new one?
  • Some insurance companies give discounts if you install a lightning rod system
  • Unrepaired damages or maintenance on a home may lead to unnecessary damages in the event of a storm - most policies do not cover the results of such neglect - have your agent inspect your home for potential problems and get them fixed
  • It's best to use non-flammable paint in and around your home to minimize fire damage caused by lightning or lightning caused brush fires
  • Broken windows are subject to your policy deductible, however, most insurers will offer an option to waive the deductible on broken windows
  • Get a fireproof file box at most home improvement stores or from your insurance agent - you need one to protect your vital papers and jewelry in case of a fire or flood

What to do if you experience a storm related loss

  • Don't panic! Get everybody, including pets, to a safe place
  • Call 911 if you have a fire or medical emergency
  • If you have damage to your home or vehicles call your insurance agent, day or night
  • Your insurance agent will make arrangements for emergency board up services, roof repair, water extraction or other damage control services needed immediately after a loss. Take pictures if you can
  • When appropriate, minimize losses by removing expensive electrical items such as laptop computers or other expensive household items
  • If you feel your loss should be covered and your agent tells you that your losses will not be covered tell them you want a claim filed anyhow. The agent may be wrong and ultimately the claims adjuster has the final say in what's covered and what's not.
  • If you experience a loss that turns out not to be covered by your policy but you thought you had that coverage you still have a chance to get compensated. You will need to file a claim with your insurance agent's Errors and Omissions policy.
  • Contact the Arizona Department of Insurance if you have any problems with an insurance carriers that were not handled to your satisfaction