Arizona, 2020Excessive Heat in Arizona, July 29 to 31, 2020
July 29 to 31, 2020 · NWS TWC · 9 events in 9 counties and zones
Very hot temperatures were experienced in southeast Arizona from July 29th through August 1st. Many locations approached or exceeded 110 degrees and set new daily record high temperatures.
Every event with a place to put it; 9 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
Open the live radar over this ground
- Deaths
- 2
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 9
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
Very hot temperatures were experienced in southeast Arizona from July 29th through August 1st. Many locations approached or exceeded 110 degrees and set new daily record high temperatures. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males on the Tohono O'odham Nation on July 30th.
What forecasters said that day
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Tucson, AZ wrote its last area forecast discussion before the first event at Jul 29, 3:05 AM MST, 7 hours 55 minutes earlier.
Area forecast discussion, Jul 29, 3:05 AM MST, 7 hours 55 minutes before
Area Forecast Discussion
National Weather Service Tucson AZ
305 AM MST Wed Jul 29 2020
.SYNOPSIS...Strong high pressure aloft today through the weekend
will provide very hot daytime temperatures, with record or near
record highs Thursday into Saturday. Thunderstorm development will
be very limited or nonexistent. Isolated to scattered thunderstorms
return early next week, although hotter than normal temperatures
will continue.
&&
.DISCUSSION...The heat will be the main story to close out July
and begin August under strong high pressure aloft parking itself
over the desert southwest. Was really surprised by some of the high
temps that were recorded on Tuesday, especially from Tucson west,
which was not handled well by the models. Believe that the dry
soil moisture due to this lack luster monsoon is giving a feedback
to the temperatures for those areas that haven't seen a lot of
rain over the past 3-4 months. With that said and see no
difference between yesterday and today, went ahead and tidy upped
the Excessive Heat Warning to include Pima, southeast Pinal and
Graham county with the addition of Santa Cruz county starting
today and continuing into Saturday. Record or near record highs
each day through Saturday. High temperatures retreat a bit on
Sunday into early next week but confidence on the low side. Could
see this extreme heat last into early next week.
With the building ridge, thunderstorm activity will basically be
relegated to the Intl border today and Thursday with little if any
activity on Friday, which should be the hottest day in this mid-
monsoon heat wave. Hints in the model world of some return of
moisture over the weekend but looks like the best chances will be
a week from now when the high moves east of the area bringing a
moister southerly flow over the area.
&&
.AVIATION...Valid through 30/12Z.
FEW-SCT clouds (locally BKN) at 10k-14k ft MSL through the forecast
period. Isolated -TSRA/-SHRA between 29/18Z and 30/04Z mostly near
the International Border SE-S of KTUS, and perhaps in the White Mtns
northeast of KSAD. Brief wind gusts near 40 kts possible with the
strongest TSRA. SFC wind variable in direction and less than 12 kts
aside from possible tstm gusts. Aviation discussion not updated for
TAF amendments.
&&
.FIRE WEATHER...Expect mainly dry conditions across southeast
Arizona today through Friday. Any thunderstorms of significance
should be limited to near the International Border and perhaps the
White Mountains. Isolated to scattered thunderstorms are forecast to
return this weekend into early next week, with the bulk of coverage
east to south of Tucson. 20-foot winds will generally follow typical
diurnal patterns at less than 15 mph apart from thunderstorm wind
gusts. High temperatures will be 5-10 degrees above normal through
at least Saturday.
&&
CLIMATE...Hot, record to near record, high temperatures to close
out the month of July. Below is a listing of record highs for the
29th through the 31st.
DATE Jul 29 Jul 30 Jul 31
FCST RCD/YR FCST RCD/YR FCST RCD/YR
TUCSON INTL AIRPORT 108 110/1995 110 109/1986 111 111/1986
AJO 111 111/1964 113 113/1972 114 117/1995
ORGAN PIPE CACTUS 110 114/1995 112 113/1957 113 114/1986
PICACHO PEAK 109 118/1995 112 113/1995 113 114/1996
SAFFORD AG STATION 106 113/1995 109 106/1995 110 108/1995
SIERRA VISTA FD 98 103/1995 100 101/1957 101 101/1986
TOMBSTONE 97 106/1995 101 105/1986 102 105/1986
WILLCOX 99 103/2019 103 105/1972 104 106/1972
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning from 11 AM this morning to 8 PM MST
Saturday for AZZ501>506-509.
&&
Visit us on Facebook...Twitter...YouTube...and at weather.gov/TucsonExcessive Heat, Western Pima County
- When
- July 29, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- Western Pima County forecast zone
- Reported by
- Mesonet
- Coordinates
- 32.097, -111.790 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 18 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached July 29 through July 31. High temperatures on July 29 included 113 degrees at Ajo, 110 at Sells, and 109 at Picacho and Safford Airport. On July 30 highs included 115 degrees at Ajo, 113 (records) at Duncan and Safford Airport, 112 at Picacho, 111 (tie) at Sells, 110 at Tucson International Airport and 107 (record) at Nogales Airport. On July 31 highs included 113 degrees at Ajo, 112 at Picacho and Fort Thomas (record), and 110 at Tucson International Airport and Duncan. Very hot temperatures continued on August 1st. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males on the Tohono O'odham Nation on July 30th, one near Topawa and another near San Miguel.
Excessive Heat, Tohono O Odham Nation
- When
- July 29, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- Tohono O Odham Nation forecast zone
- Deaths
- 2 direct, 0 indirect
- Reported by
- County Official
- Coordinates
- 32.501, -111.567 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 18 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached July 29 through July 31. High temperatures on July 29 included 113 degrees at Ajo, 110 at Sells, and 109 at Picacho and Safford Airport. On July 30 highs included 115 degrees at Ajo, 113 (records) at Duncan and Safford Airport, 112 at Picacho, 111 (tie) at Sells, 110 at Tucson International Airport and 107 (record) at Nogales Airport. On July 31 highs included 113 degrees at Ajo, 112 at Picacho and Fort Thomas (record), and 110 at Tucson International Airport and Duncan. Very hot temperatures continued on August 1st. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males on the Tohono O'odham Nation on July 30th, one near Topawa and another near San Miguel.
Excessive Heat, Upper Santa Cruz River and Altar Valleys
- When
- July 29, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- Upper Santa Cruz River and Altar Valleys forecast zone
- Reported by
- Mesonet
- Coordinates
- 31.812, -111.318 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 18 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached July 29 through July 31. High temperatures on July 29 included 113 degrees at Ajo, 110 at Sells, and 109 at Picacho and Safford Airport. On July 30 highs included 115 degrees at Ajo, 113 (records) at Duncan and Safford Airport, 112 at Picacho, 111 (tie) at Sells, 110 at Tucson International Airport and 107 (record) at Nogales Airport. On July 31 highs included 113 degrees at Ajo, 112 at Picacho and Fort Thomas (record), and 110 at Tucson International Airport and Duncan. Very hot temperatures continued on August 1st. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males on the Tohono O'odham Nation on July 30th, one near Topawa and another near San Miguel.
Excessive Heat, Tucson Metro Area
- When
- July 29, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- Tucson Metro Area forecast zone
- Reported by
- Mesonet
- Coordinates
- 32.097, -111.790 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 18 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached July 29 through July 31. High temperatures on July 29 included 113 degrees at Ajo, 110 at Sells, and 109 at Picacho and Safford Airport. On July 30 highs included 115 degrees at Ajo, 113 (records) at Duncan and Safford Airport, 112 at Picacho, 111 (tie) at Sells, 110 at Tucson International Airport and 107 (record) at Nogales Airport. On July 31 highs included 113 degrees at Ajo, 112 at Picacho and Fort Thomas (record), and 110 at Tucson International Airport and Duncan. Very hot temperatures continued on August 1st. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males on the Tohono O'odham Nation on July 30th, one near Topawa and another near San Miguel.
Excessive Heat, South Central Pinal County
- When
- July 29, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- South Central Pinal County forecast zone
- Reported by
- Mesonet
- Coordinates
- 32.904, -111.345 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 18 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached July 29 through July 31. High temperatures on July 29 included 113 degrees at Ajo, 110 at Sells, and 109 at Picacho and Safford Airport. On July 30 highs included 115 degrees at Ajo, 113 (records) at Duncan and Safford Airport, 112 at Picacho, 111 (tie) at Sells, 110 at Tucson International Airport and 107 (record) at Nogales Airport. On July 31 highs included 113 degrees at Ajo, 112 at Picacho and Fort Thomas (record), and 110 at Tucson International Airport and Duncan. Very hot temperatures continued on August 1st. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males on the Tohono O'odham Nation on July 30th, one near Topawa and another near San Miguel.
Excessive Heat, Southeast Pinal County
- When
- July 29, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- Southeast Pinal County forecast zone
- Reported by
- Mesonet
- Coordinates
- 32.904, -111.345 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 18 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached July 29 through July 31. High temperatures on July 29 included 113 degrees at Ajo, 110 at Sells, and 109 at Picacho and Safford Airport. On July 30 highs included 115 degrees at Ajo, 113 (records) at Duncan and Safford Airport, 112 at Picacho, 111 (tie) at Sells, 110 at Tucson International Airport and 107 (record) at Nogales Airport. On July 31 highs included 113 degrees at Ajo, 112 at Picacho and Fort Thomas (record), and 110 at Tucson International Airport and Duncan. Very hot temperatures continued on August 1st. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males on the Tohono O'odham Nation on July 30th, one near Topawa and another near San Miguel.
Excessive Heat, Upper Gila River and Aravaipa Valleys
- When
- July 29, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- Upper Gila River and Aravaipa Valleys forecast zone
- Reported by
- Mesonet
- Coordinates
- 33.074, -109.563 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 18 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached July 29 through July 31. High temperatures on July 29 included 113 degrees at Ajo, 110 at Sells, and 109 at Picacho and Safford Airport. On July 30 highs included 115 degrees at Ajo, 113 (records) at Duncan and Safford Airport, 112 at Picacho, 111 (tie) at Sells, 110 at Tucson International Airport and 107 (record) at Nogales Airport. On July 31 highs included 113 degrees at Ajo, 112 at Picacho and Fort Thomas (record), and 110 at Tucson International Airport and Duncan. Very hot temperatures continued on August 1st. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males on the Tohono O'odham Nation on July 30th, one near Topawa and another near San Miguel.
Excessive Heat, Upper San Pedro River Valley
- When
- July 30, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- Upper San Pedro River Valley forecast zone
- Reported by
- Mesonet
- Coordinates
- 32.109, -110.569 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 16 degrees above normal occurred in Cochise County, causing the High Heat Risk category to be reached July 30 and July 31. On July 30 highs included 110 degrees at Cascabel and 107 (record) at McNeal. On July 31 record highs included 111 degrees (tie) at Cascabel, 109 at San Simon and 106 at Tombstone. Very hot temperatures continued on August 1st.
Excessive Heat, Eastern Cochise County Below 5000 Feet
- When
- July 30, 11:00 AM MST to July 31, 11:59 PM MST
- Where
- Eastern Cochise County Below 5000 Feet forecast zone
- Reported by
- Mesonet
- Coordinates
- 31.880, -109.751 (the zone’s center; the record gives no point)
Very hot temperatures 7 to 16 degrees above normal occurred in Cochise County, causing the High Heat Risk category to be reached July 30 and July 31. On July 30 highs included 110 degrees at Cascabel and 107 (record) at McNeal. On July 31 record highs included 111 degrees (tie) at Cascabel, 109 at San Simon and 106 at Tombstone. Very hot temperatures continued on August 1st.
- Excessive Heat
- Heat at or above the local excessive heat warning criteria, or heat that caused deaths.
After NWS Directive 10-1605, the rules offices file Storm Data by.
- Tropical Storm and Flash Flooding in Puerto Rico, July 29 to 30, 20201 death · $13 million · 50 kt wind · 36 events
- Tornado and Damaging Winds in New York, July 29, 2020$75,000 · EF0 · 27 events
- Damaging Winds in New York, July 29, 2020$55,000 · 50 kt wind · 7 events
- Hail and Damaging Winds in Kansas, July 29, 20201 in hail · 17 events
- Flash Flooding in Kansas, July 29, 202014 events
- Flash Flooding and Flooding in Missouri, July 29 to 31, 202012 events
- Flash Flooding in Nebraska, July 29, 20209 events
- Damaging Winds in Kansas, July 29 to 30, 202070 kt wind · 8 events
- Hail and Damaging Winds in Kansas, July 29, 20201.25 in hail · 7 events
- Flash Flooding and Heavy Rain in South Carolina, July 29, 2020$2,000 · 5 events
- Damaging Winds in Colorado, July 29, 202056 kt wind · 4 events
- Flash Flood and Hail in Nebraska, July 29, 2020$10,000 · 1.5 in hail · 3 events
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 912480, 912481, 912482, 912490, 912491, 912492, 912493, 912488, 912489.