National Weather Service United States Department of Commerce
Top 10 weather/water/climate stories to impact the Tucson metro area during the 20th century

Editors note: As the 20th century drew to a close, National Weather Service office staff in Tucson reviewed records on major events that affected the Tucson metro area since 1900. The criteria was based on impacts to people, property and dollar damage. Choosing among the numerous 20th century weather events was a difficult task. Like all lists of this type, the order of significance is open to debate.

The top 10 weather/water/climate stories to impact Tucson this century (in decending order)

10). November 16 1958 - Earliest and heaviest snow event on record. Three boy scouts died.

6.4 inches of snow across the metro area caused auto accidents, stranded people, dropped power lines, knocked out telephone service, closed highways and paralyzed air travel.  Three boy scouts were stranded in snow near Madera Canyon in the Santa Rita Mountains south of Tucson.  Their bodies were not found for two weeks.  The heavy snow also closed the highway to Mt. Lemmon, marooning about 35 weekend vacationers.

 9). July 24 1975 - City wide damage due to violent thunderstorm

The most violent thunderstorm in over a decade mauled the city for 90 minutes, with wind gusts to 67 mph and heavy rain which caused city-wide damage estimated at $2,000,000 (1975 dollars).  A commercial hanger had its roof ripped off and ten airplanes were severely damaged.  The entire roof of a large apartment was blown off making 52 units uninhabitable and 200 persons temporarily homeless.  Power lines were down at almost 100 locations as poles were snapped like matchsticks.

 8). August 9 1945 - Flash flooding leads to 10 deaths

Thunderstorms with heavy rain filled to overflowing the banks of an ordinarily dry wash on Tucson's southside.  Flood waters washing down this normally dry wash tore a 15-foot gap in the three-mile bridge on the Benson Highway.  Four automobiles plunged into the raging torrents where 10 people were drowned while four others struggled out of the flood waters.

 7). August 27 1964 - First tornado death in state

A tornado moved through an Indian village southwest of Tucson demolishing four homes, killing two people and injuring eight, all from one family.  This was the first tornado reported in Arizona that cuased a death.  Property damage was done to the convent of the Nuns of St. Francis.  The nearby historic San Xavier Mission escaped with only minor structural damage.

 6). June 23 1974 - Tornado kills one and injures 40

One man was killed and 40 people were injured as a tornado ripped through a mobile park about one mile west of the historic San Xavier Mission, southwest of Tucson.  The tornado was estimated to be on the ground for three minutes and destroyed 19 mobile homes with severe damage to 50 others.  Three additional tornadoes were spotted and reported to law enforcement officials between 330 PM and 4 PM.

 5). December 8 1971 - Most snow ever recorded in Tucson

6.8 inches of snow blankets the Tucson metro area after midnight.  The heavy snow snarled traffic, closed the airport, downed power lines and damaged or destroyed 3000 trees, some of them 20 years old.  Slush on the runway forced the closure of the Tucson International Airport and cancellation of flights between 6 AM and 11 AM.  At the time, the airport did not own a snow plow.

 4). Summer of 1994 - Hottest meteorological summer on record

Sweltering heat plaqued the area during the summer of 1994 (June through August) and resulted in the warmest summer on record.  Monthly average temperature records were set for all three months (June 89.2 degrees, old record 88.6 degrees in 1990; July 90.4 degrees, old record 89.9 degrees in 1989; and August 90.2 degrees, old record 86.9 degrees in 1962).  The mercury topped 100 degrees on 82 of the 92 summer days of 1994.  For the year, 99 days were recorded with high temperatures of 100 degrees or more.  Records were also set for consecutive days with high temperatures of 105 degrees or more (24 days - June 23rd to July 16th, old record was 15 days in 1990 - June 17th to July 1st) and 110 degrees or more (6 days - June 24th to 29th, old record was 5 days in 1990 - June 24th to 28th).  The second, third and fourth hottest days on record were recorded in the summer of 1994 (116 degrees on June 29th and 115 degrees on June 25th and 28th).  Overall the summer of 1994 had 19 record highs that were set or tied...7 days came within one degree of tieing a record and four days came within two degrees of tieing a record.

 3). July 26 1981 - Flash flood kills 8 at popular recreational spot northeast of Tucson.

Eight people were killed in a flash flood at Tanque Verde Falls, a popular recreational spot northeast of Tucson, when a wall of water 15 feet high rushed down the canyon and over the 100 foot falls.  This was the second of three flash flood events that occurred in this area between July 25th and 30th.  This event occurred around 4 PM when the area was full of swimmers and picnickers.  The other two events occurred at times when few people were in the area.

 2). January 1993 - Flood event over two week period

In a two week period the area was hit with several Pacific storm systems which produced the wettest January on record and widespread flooding across the metro area.  Between four and seven inches of rain fell across the metro area and in the surrounding mountains between the 5th and 19th.  Runoff from snow melt from the Santa Catalina Mountains added to the flood woes.  The floods of January 1993 were the most significant to impact Pima county since the October 1983 flood.  Damage to public transportation and flood control facilities, private property and inconvenience totaled up to roughly 14 million dollars for emergency repairs and long-term improvements.  Improved design and construction practices developed in response to the October 1983 flood helped to minimize the amount of damage incurred and saved lives as none were lost during the flood event.

and the Number 1 weather story to affect Tucson this century was:

the October 1983 flood

Prior to the flood, nearly seven inches of rain fell during August and September which saturated the soil around the metro area.  The wet antecedent conditions were present when on September 30th, a weather disturbance entered Arizona at the same time a surge of moisture from Tropical Storm Octave, which was located off the central Baja California coast, moved northeast across the area.  The result over the four day period was torrential rains with totals across the metro area ranging from five to nine inches, causing a very destructive flood in Tucson and southeast Arizona.  Bridges in the metro area, including all spanning the Santa Cruz River except one, were damaged or partially washed away.  Additional damage occurred along the watercourses located throughout the metro area.  Several buildings fell into Rillito Creek due to bank erosion. Extensive damage also occurred to agriculture in Marana. Cost estimates (using 1984 dollars) to repair and mitgate flood damage were estimated at $105.7 million.  Four deaths in Eastern Pima County were associated  with the flood.

Honorable mention (events shown from earliest to latest)

1905 - Coldest and wettest year on record
The yearly average temperature of 65.0 degrees still stands (tied with 1912) as the coldest year on record.  The average monthly temperature for April (58.3 degrees, monthly rank 2nd), May (64.6 degrees, monthly rank 1st) and June (77.6 degrees, monthly rank 2nd) are the coldest for these months on record.  The monthly precipitation records still stand for February (4.15"), March (3.88"), April (3.53") and November (4.61").

January 7 1913 - Coldest temperature officially recorded in Tucson
The mercury bottomed out at a very cold 6 degrees on the morning of the 7th with some low-lying areas in Tucson reporting temperatures as low as zero.

December 20-24 1914 - Heavy rains and floodingkills two and damage city weils
Most rainfall ever recorded in a five day period in December (3.85") led to overflowing of all streams and dry channels.  The resulting damage was the greatest south of Tucson.  The roaring Santa Cruz River nearly washed away the Congress street bridge, flooded the valley and sent stranded residents into tree tops, house tops and windmills.  Two people died in the storm.  The flood also caused severe damage to the city wells south of town.

September 24-25 1976 - Flash flooding and hail
Tropical moisture brought heavy thunderstorms with intermittent hail to the area that rapidly filled the normally dry washes, especially the Pantano Wash and Rillito Creek.  Flooding occurred on almost 100 streets and roads throughout the city, particularly on the north and east side, where local amouts of rain ranged to 3.5".  Nearly a dozen cars, some with occupants, where swept into washes on the east side. Sizes of hail ranged upward to 3/4" diameter, with some as big as golf balls.  Up to 5 inches of hail covered the ground in the Mt. Lemmon area.

October 6-10 1977 - Flood event
Mositure from Tropical storm Heather brought heavy rainfall during the four day period south of Tucson.  The runoff from the storm caused the Santa Cruz river to have, at that time, the highest discharge known since 1892 that resulted in severe flooding.

December 25 1987 and 1916 - White Christmas across Tucson
Up to three inches of snow blanketed the metro area in 1987.  This was the first white Christmas in Tucson since 1916 when four inches fell.

June 26 1990 - Hottest temperature officially recorded in Tucson
The mercury topped out at 117 degrees on the afternoon of the 26th setting an all-time high temperature in Tucson.