National Weather Service United States Department of Commerce

Current Temperatures



Current Heat Index Temperatures



Current Wet Bulb Globe Temperatures


Max Temperature vs Heat Index


The Heat Index is a measure of how hot it really feels when relative humidity is factored in with the actual air temperature. To find the Heat Index temperature, look at the Heat Index Chart above or check our Heat Index Calculator. As an example, if the air temperature is 96°F and the relative humidity is 65%, the heat index--how hot it feels--is 121°F. The red area without numbers indicates extreme danger. The National Weather Service will initiate alert procedures when the Heat Index is expected to exceed 105°-110°F (depending on local climate) for at least 2 consecutive days.



Compare the Max Temperature and Heat Index


(Prototype -- not official -- availability not guaranteed)

* (Experimental) National WBGT Display *


The Wet Bulb Globe Temperature (WBGT) is a measure of heat stress in direct sunlight, which is based on temperature, humidity, wind speed, sun angle, and cloud cover (solar radiation). This differs from the heat index, which is based only on temperature and humidity and is calculated for shady areas. Scroll down for latest forecasts.




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WBGT vs Heat Index


What's the Difference?


Compare the WBGT and Heat Index


Heat Headlines


  • Excessive Heat Warning—Take Action! An Excessive Heat Warning is issued within 12-24 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this Warning is when the maximum heat index temperature is expected to be 105° or higher. If you don't take precautions immediately when conditions are extreme, you may become seriously ill or even die.

  • Heat Advisory—Take Action! A Heat Advisory is issued within 12-24 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this Advisory is when the maximum heat index temperature is expected to be 95° or higher. Take precautions to avoid heat illness. If you don't take precautions, you may become seriously ill or even die.

  • Excessive Heat Watches—Be Prepared! Heat watches are issued when conditions are favorable for an excessive heat event in the next 24 to 48 hours. A Watch is used when the risk of a heat wave has increased but its occurrence and timing is still uncertain.


Heat Index Advisory Criteria


Heat Index Warning Criteria


Heat Safety




During extremely hot and humid weather, your body's ability to cool itself is challenged. When the body heats too rapidly to cool itself properly, or when too much fluid or salt is lost through dehydration or sweating, body temperature rises and you or someone you care about may experience a heat-related illness. It is important to know the symptoms of excessive heat exposure and the appropriate responses. The Centers for Disease Control and Prevention (CDC) provides a list of warning signs and symptoms of heat illness, and recommended first aid steps. Some of these symptoms and steps are listed below.

Heat Cramps


Heat cramps may be the first sign of heat-related illness, and may lead to heat exhaustion or stroke.
  • Symptoms: Painful muscle cramps and spasms usually in legs and abdomen and Heavy sweating.
  • First Aid: Apply firm pressure on cramping muscles or gently massage to relieve spasm. Give sips of water unless the person complains of nausea, then stop giving water.

    Seek immediate medical attention if cramps last longer than 1 hour.


Heat Exhaustion


  • Symptoms: Heavy sweating, Weakness or tiredness, cool, pale, clammy skin; fast, weak pulse, muscle cramps, dizziness, nausea or vomiting, headache, fainting,
  • First Aid: Move person to a cooler environment, preferably a well air conditioned room. Loosen clothing. Apply cool, wet cloths or have person sit in a cool bath. Offer sips of water. If person vomits more than once,

    Seek immediate medical attention if the person vomits, symptoms worsen or last longer than 1 hour


Heat Stroke


  • Symptoms: Throbbing headache, confusion, nausea, dizziness, body temperature above 103°F, hot, red, dry or damp skin, rapid and strong pulse, fainting, loss of consciousness.
  • First Aid: Call 911 or get the victim to a hospital immediately. Heat stroke is a severe medical emergency. Delay can be fatal. Move the victim to a cooler, preferably air-conditioned, environment. Reduce body temperature with cool cloths or bath. Use fan if heat index temperatures are below the high 90s. A fan can make you hotter at higher temperatures. Do NOT give fluids.


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