Arizona, 2020Excessive Heat and Heat in Arizona, August 13 to 19, 2020
August 13 to 19, 2020 · NWS TWC · 8 events in 7 counties and zones
An extended period of very hot temperatures were experienced in southeast Arizona from August 13th-19th. Many locations approached or exceeded 110 degrees and set new daily record high temperatures.
Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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- Deaths
- 4
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 8
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.
An extended period of very hot temperatures were experienced in southeast Arizona from August 13th-19th. 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 four adult males during the period, two each in Pima and Santa Cruz counties.
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 Aug 13, 9:48 AM MST, 12 minutes earlier.
Area forecast discussion, Aug 13, 9:48 AM MST, 12 minutes before
Area Forecast Discussion
National Weather Service Tucson AZ
948 AM MST Thu Aug 13 2020
.SYNOPSIS...An extended period of excessive heat can be anticipated
Thursday into next week as high pressure aloft strengthens over the
region. There might be a break in the heat from time-to-time as a
chance of showers and thunderstorms remain in the forecast. The
weather pattern will become favorable next week for a daily dose of
thunderstorms more typical of the monsoon season.
&&
.DISCUSSION...No changes to the current message of excessive heat
as an extended period of hotter conditions commences today and
continues through next week. The increase in moisture the past
couple of days will help support isolated to scattered afternoon and
evening thunderstorms through the weekend. The weather pattern will
become favorable for daily thunderstorm activity more typical of the
monsoon season next week. Please refer to the additional sections in
this product for more details.
&&
.AVIATION...Valid through 14/18Z.
FEW-SCT clouds AOA 10-15k ft MSL for SE AZ this morning. Isolated to
scattered -TSRA/-SHRA mainly from KTUS south and east during the
afternoon and early evening hours. SFC wind generally less than 12
kts through the forecast period, with WLY/NWLY winds in the
afternoon and early evening and SFC wind variable in direction at
other times. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Isolated to at times scattered afternoon and
evening showers and thunderstorms are forecast the next 7 days,
primarily south and east of Tucson. Temperatures will remain hot and
moisture generally drier compared to average. 20-foot winds will
follow typical diurnal patterns at less than 15 mph outside of any
thunderstorm wind gusts. Daytime humidity will generally be in the
15 to 25 percent range in the valleys and 20 to 30 percent in the
mountains with moderate to good overnight recoveries.
&&
.PREV DISCUSSION (253 AM MST Thu)...Our two main concerns are the
strong high pressure setting up overhead and a moisture increase
that has brought our available moisture pool much closer to average
over the past 48 hours. Overall, heat will be our biggest concern
into next week as we will likely see a sustained period of
temperatures 10 to 15 degrees above average, with records threatened
on most days between now and early to mid next week. An Excessive
Heat Warning is in effect through Monday, but may ultimately need to
be extended. Tucson Airport should make a strong push toward 110 on
at least a couple of these days.
The only thing to ameliorate the temperatures would be clouds and
thunderstorms. We have a much better chance today than we did to
start the week, with surface dew points solidly back into the 50s
and precipitable water back up to 1.2 to 1.5 inches (east to west).
As the high strengthens overhead, the already (relatively) warm mid
levels have room to warm another degree or two. Not great for
thunderstorms, but if you give it enough sunshine, the excessive
surface heating will get past that on some days.
Especially if we are able to set up a source for strong late
afternoon or early evening outflows. One such day could be Sunday,
when the high center wobbles far enough north to bring in an
easterly guiding flow for potential outflow off the Mogollon Rim.
At any rate, below average coverage most days with a couple of solid
thunderstorm days mixed in. Pending a peek at the morning sounding,
today could be a decent general thunderstorm day for a scattering of
short-lived airmass style thunderstorms. Sunday has the potential
for decent timing on organized outflows pushing into the lower
deserts.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning from 10 AM this morning to 8 PM MST Sunday
for AZZ503-509.
Excessive Heat Warning from 10 AM this morning to 8 PM MST Monday
for AZZ501-502-504>506.
&&
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Excessive Heat, Western Pima County
- When
- August 13, 10:00 AM MST to August 19, 8:00 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 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached August 13 through August 19. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on August 18; 114 at Organ Pipe Cactus National Monument on August 17 and 18; 113 at Picacho on the 18th; 111 at both Sells on the 16th and 17th and at Tucson International Airport on the 13th; 109 at Green Valley on the 17th; and 106 at San Manuel on the 14th and 15th. Low temperatures during this period were as warm as 84 at Tucson and 89 at Ajo. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males, one near Guvo on the Tohono O'odham Nation on August 13th and one on the grounds of the Ironwood National Forest on August 14th.
Excessive Heat, Tohono O Odham Nation
- When
- August 13, 10:00 AM MST to August 19, 8:00 PM MST
- Where
- Tohono O Odham Nation forecast zone
- Deaths
- 1 direct, 0 indirect
- Reported by
- County Official
- Coordinates
- 32.501, -111.567 (the zone’s center; the record gives no point)
Very hot temperatures 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached August 13 through August 19. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on August 18; 114 at Organ Pipe Cactus National Monument on August 17 and 18; 113 at Picacho on the 18th; 111 at both Sells on the 16th and 17th and at Tucson International Airport on the 13th; 109 at Green Valley on the 17th; and 106 at San Manuel on the 14th and 15th. Low temperatures during this period were as warm as 84 at Tucson and 89 at Ajo. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males, one near Guvo on the Tohono O'odham Nation on August 13th and one on the grounds of the Ironwood National Forest on August 14th.
Excessive Heat, Tucson Metro Area
- When
- August 13, 10:00 AM MST to August 19, 8:00 PM MST
- Where
- Tucson Metro Area forecast zone
- Deaths
- 1 direct, 0 indirect
- Reported by
- County Official
- Coordinates
- 32.097, -111.790 (the zone’s center; the record gives no point)
Very hot temperatures 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached August 13 through August 19. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on August 18; 114 at Organ Pipe Cactus National Monument on August 17 and 18; 113 at Picacho on the 18th; 111 at both Sells on the 16th and 17th and at Tucson International Airport on the 13th; 109 at Green Valley on the 17th; and 106 at San Manuel on the 14th and 15th. Low temperatures during this period were as warm as 84 at Tucson and 89 at Ajo. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males, one near Guvo on the Tohono O'odham Nation on August 13th and one on the grounds of the Ironwood National Forest on August 14th.
Excessive Heat, South Central Pinal County
- When
- August 13, 10:00 AM MST to August 19, 8:00 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 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached August 13 through August 19. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on August 18; 114 at Organ Pipe Cactus National Monument on August 17 and 18; 113 at Picacho on the 18th; 111 at both Sells on the 16th and 17th and at Tucson International Airport on the 13th; 109 at Green Valley on the 17th; and 106 at San Manuel on the 14th and 15th. Low temperatures during this period were as warm as 84 at Tucson and 89 at Ajo. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males, one near Guvo on the Tohono O'odham Nation on August 13th and one on the grounds of the Ironwood National Forest on August 14th.
Excessive Heat, Southeast Pinal County
- When
- August 13, 10:00 AM MST to August 19, 8:00 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 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached August 13 through August 19. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on August 18; 114 at Organ Pipe Cactus National Monument on August 17 and 18; 113 at Picacho on the 18th; 111 at both Sells on the 16th and 17th and at Tucson International Airport on the 13th; 109 at Green Valley on the 17th; and 106 at San Manuel on the 14th and 15th. Low temperatures during this period were as warm as 84 at Tucson and 89 at Ajo. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two adult males, one near Guvo on the Tohono O'odham Nation on August 13th and one on the grounds of the Ironwood National Forest on August 14th.
Excessive Heat, Upper Santa Cruz River and Altar Valleys
- When
- August 13, 10:00 AM MST to August 16, 8:00 PM MST
- Where
- Upper Santa Cruz River and Altar Valleys forecast zone
- Deaths
- 1 direct, 0 indirect
- Reported by
- County Official
- Coordinates
- 31.812, -111.318 (the zone’s center; the record gives no point)
Very hot temperatures 10 to 15 degrees above normal occurred in parts of southeast Arizona, causing the High Heat Risk category to be reached August 13 through August 16. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 113 degrees at Safford Airport on August 15; 111 at both Fort Thomas on the 15th and 16th and Sasabe on the 14th; 110 at Duncan on the 15th; and 104 at Nogales Airport on the 13th and 15th. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male near Ruby on August 16th.
Excessive Heat, Upper Gila River and Aravaipa Valleys
- When
- August 13, 10:00 AM MST to August 16, 8:00 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 10 to 15 degrees above normal occurred in parts of southeast Arizona, causing the High Heat Risk category to be reached August 13 through August 16. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 113 degrees at Safford Airport on August 15; 111 at both Fort Thomas on the 15th and 16th and Sasabe on the 14th; 110 at Duncan on the 15th; and 104 at Nogales Airport on the 13th and 15th. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male near Ruby on August 16th.
Heat, Upper Santa Cruz River and Altar Valleys
- When
- August 17, 10:00 AM MST to 8:00 PM MST
- Where
- Upper Santa Cruz River and Altar Valleys forecast zone
- Deaths
- 1 direct, 0 indirect
- Reported by
- County Official
- Coordinates
- 31.812, -111.318 (the zone’s center; the record gives no point)
Hot and above normal temperatures around 100 degrees occurred in parts of Santa Cruz County causing the Moderate Heat Risk category to be reached on August 17. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male near Patagonia.
- Excessive Heat
- Heat at or above the local excessive heat warning criteria, or heat that caused deaths.
- Heat
- Heat below excessive heat criteria that still caused deaths, injuries or significant impacts.
After NWS Directive 10-1605, the rules offices file Storm Data by.
- Tornadoes and Flash Flooding in Minnesota, August 13 to 14, 2020$385,000 · EF2 · 27 events
- Excessive Heat in California, August 13 to 20, 20201 death · 11 events
- Hail and Damaging Winds in North Dakota, August 13 to 14, 2020$569,000 · 1.75 in hail · 20 events
- Wildfire in Texas, August 13 to 16, 2020$300,000 · 1 event
- Wildfire in California, August 13 to 28, 20208 injured · 1 event
- Damaging Winds and Lightning Strikes in Georgia, August 13 to 14, 2020$162,000 · 4 events
- Flash Flood in Indiana, August 13, 2020$150,000 · 1 event
- Tornadoes and Hail in Minnesota, August 13, 2020EF1 · 28 events
- Flash Flood and Hail in Oklahoma, August 13, 2020$52,000 · 1.75 in hail · 11 events
- Flash Flooding and Flooding in Virginia, August 13, 202023 events
- Heat in Texas, August 13, 202021 events
- Heat in Louisiana, August 13, 20209 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: 919156, 919161, 919162, 919163, 919164, 919167, 919168, 919158.