Which Arizona counties run hottest
The low-desert counties lead on every heat measure. Yuma County's station records 118.2 days a year at or above 100 F and a July high of 106.7 F.[15][14] Pinal County's station logs 115.6 days and 106.6 F,[12][11] and the station for Maricopa County (Phoenix Sky Harbor) shows 111.3 days and 106.5 F.[9][8]

La Paz County's Parker station tops them all at 126.3 days.[7]
| County station | Days at or above 100 F | July high |
|---|---|---|
| Yuma | 118.2 | 106.7 F |
| Pinal | 115.6 | 106.6 F |
| Maricopa (Phoenix Sky Harbor) | 111.3 | 106.5 F |
| Cochise (Bisbee) | 0.3 | 87.4 F |
| Coconino | 0.0 | Not listed |
The cool end is the high country. Coconino County's station has 0.0 days at or above 100 F.[4] Cochise County's Bisbee station has 0.3 days and a July high of 87.4 F.[2][1]
Normals are not records. They describe a typical summer, not the hottest day on file.
For a month-by-month view, see the Phoenix and Arizona temperature by month page.
How we picked each county's weather station
Each row uses one NOAA station near the county seat, or the nearest active normals station within the distance stated in that row. Most stations sit within 10 miles of the seat. Two counties do not: the Greenlee County row uses Duncan, 23 miles from Clifton,[5] and the Navajo County row uses Winslow Municipal Airport, 34 miles from Holbrook.[10]
A county average would blend desert floor and mountain stations into a number that describes no place anyone lives.
Read each figure as the weather at that station, not the whole county. Homes at a different elevation in the same county can run noticeably hotter or cooler.
What the monsoon column measures
The monsoon column adds the July, August and September rain normals at each station. NOAA's normals are monthly, so they cannot be cut to the official season of June 15 through September 30.[21] The column therefore misses June 15 to 30 and includes all of September.
Rain varies sharply by county.
Cochise County's station gets 10.04 inches and Santa Cruz County's gets 9.73 inches.[1][13] La Paz County's gets 1.02 inches and Yuma County's 1.12 inches.[6][14]
Depth
July to September rain normals
Ground level
- 1.02 inchesLa Paz
- 1.12 inchesYuma
- 9.73 inchesSanta Cruz
- 10.04 inchesCochise
NWS Phoenix notes that the monsoon share of annual rain ranges from under 20% in extreme western Arizona to nearly 70% in eastern mountain areas.[22] A normal also says nothing about where one storm lands.
For prep steps, read monsoon season dates and home prep.
Why the table has no 110-degree count
NOAA's normals publish days at or above 100 F, but no 110 F day count, so the table has none.
The 100 F count is the heat measure available for all 15 counties.
The National Weather Service does publish 110 F counts for a few cities, including Phoenix. Those figures are not part of the county normals used here, so they are not mixed in.
Where to find live heat and storm warnings
Four National Weather Service offices cover Arizona counties:
- NWS Phoenix: Gila, La Paz, Maricopa, Pinal and Yuma. See its heat page[19] and monsoon and dust storm page.[20]
- NWS Tucson: Cochise, Graham, Greenlee, Pima and Santa Cruz. Its monsoon safety page covers heat, thunderstorms and dust storms.[18]
- NWS Flagstaff: Apache, Coconino, Navajo and Yavapai.
- NWS Las Vegas: Mohave.
Flagstaff and Las Vegas have no heat or dust pages of their own, so use the national extreme heat safety[16] and wind and dust storm safety[17] pages.
For what dust storms do to a house, see haboobs and your home. If the heat is straining your cooling system, the HVAC guide covers permits and licensing.
Quick answers
Why does the table have no 110 F count?
NOAA's normals publish days at or above 100 F but no 110 F day count.
Does the monsoon column cover the whole season?
No. It adds July, August and September, so it misses June 15 to 30 and includes all of September.
Sources
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Bisbee 1Wnw (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USC00020775&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Bisbee 1Wnw (annual days at or above 100 F)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USC00020775&dataset=normals-annualseasonal-1991-2020&dataTypes=ANN-TMAX-AVGNDS-GRTH100. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Flagstaff Pulliam Airport (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00003103&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Flagstaff Pulliam Airport (annual days at or above 100 F)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00003103&dataset=normals-annualseasonal-1991-2020&dataTypes=ANN-TMAX-AVGNDS-GRTH100. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Duncan (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USC00022754&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Parker (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USC00026250&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Parker (annual days at or above 100 F)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USC00026250&dataset=normals-annualseasonal-1991-2020&dataTypes=ANN-TMAX-AVGNDS-GRTH100. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Phoenix Sky Harbor International Airport (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00023183&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Phoenix Sky Harbor International Airport (annual days at or above 100 F)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00023183&dataset=normals-annualseasonal-1991-2020&dataTypes=ANN-TMAX-AVGNDS-GRTH100. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Winslow Muni Airport (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00023194&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Casa Grande Nm (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USC00021314&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Casa Grande Nm (annual days at or above 100 F)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USC00021314&dataset=normals-annualseasonal-1991-2020&dataTypes=ANN-TMAX-AVGNDS-GRTH100. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Nogales 6 N (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USC00025924&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Yuma Mcas (monthly normals)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00003145&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Yuma Mcas (annual days at or above 100 F)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00003145&dataset=normals-annualseasonal-1991-2020&dataTypes=ANN-TMAX-AVGNDS-GRTH100. Accessed October 21, 2026.
- National Weather Service. "National Weather Service: extreme heat safety." https://www.weather.gov/safety/heat. Accessed October 21, 2026.
- National Weather Service. "National Weather Service: wind and dust storm safety." https://www.weather.gov/safety/wind-dust-storm. Accessed October 21, 2026.
- National Weather Service. "NWS Tucson monsoon safety (heat, thunderstorm and dust storm)." https://www.weather.gov/twc/monsoonsafety. Accessed October 21, 2026.
- National Weather Service. "NWS Phoenix heat safety." https://www.weather.gov/psr/heat. Accessed October 21, 2026.
- National Weather Service. "NWS Phoenix dust storm and monsoon safety." https://www.weather.gov/psr/MonsoonSafety. Accessed October 21, 2026.
- National Weather Service, Flagstaff. "Northern Arizona Monsoon Season." https://www.weather.gov/fgz/monsooninfo. Accessed October 21, 2026.
- National Weather Service, Phoenix. "2024 Monsoon Season Review." https://www.weather.gov/psr/2024MonsoonSeasonReview. Accessed October 21, 2026.