Phoenix, AZ weather in August
Expect very hot, mostly dry weather in Phoenix in August, with highs near 105°F and lows near 84°F. Rain falls on about 5 days. It is one of the warmest months in Phoenix. Plan outdoor time for mornings and evenings.
- Normal high
- 105°F
- Normal low
- 84°F
- Wet days
- 5
- 0.9 in total
- Muggy days
- 5
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 106°F | 104°F |
| Normal low | 85°F | 82°F |
| Chance of a wet day | 15% | 13% |
| Sunrise / sunset | 5:40 am / 7:28 pm | 6:01 am / 6:55 pm |
| Daylight | 13.8 h | 12.9 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Arizona time (no daylight saving)).
A typical August day
- 6 am85°Fdew point 61°F
- 9 am91°Fdew point 60°F
- Noon98°Fdew point 58°F
- 3 pm103°Fdew point 56°F
- 6 pm102°Fdew point 55°F
- 9 pm96°Fdew point 57°F
NOAA hourly normals (local standard time) from Phoenix Sky Harbor Intl Airport (4 mi away); average wind 7 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F0 of 31
- Hot dayshigh 90°F or more31 of 31
- Muggy daysdaily mean dew point 65°F or more5 of 31
- Wet daysat least 0.01 in of rain or melted snow5 of 31
- Notable rainat least 0.10 in2 of 31
- Freezing nightslow 32°F or below0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 0.9 in; a dry August brings about 0.3 in and a wet one about 1.3 in (25th and 75th percentiles). About 1 day brings half an inch or more.
How August varies from year to year
- Warmest August, 1991-20202020: average high 111°F
- Coolest August2014: average high 102°F
- Wettest August2008: 3.5 in
- Driest August2002: no measurable precipitation
- Highest reading117°F (August 14, 2020)
- Lowest reading64°F (August 28, 2008)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 107°F | 105°F | 100°F |
| Normal low | 85°F | 84°F | 78°F |
| Wet days | 4 | 5 | 3 |
| Comfortable days | 0 | 0 | 0 |
| Daylight | 14.1 h | 13.4 h | 12.4 h |
Highs change by -2°F from July and -5°F into September.
Nearby alternatives in August
- Drier: Yuma, AZ156 mi · high 106°F · 1 wet day
- Cooler: Sedona, AZ100 mi · high 94°F · 9 wet days
How Phoenix ranks in August
- Normal high6th warmest of 378 cities; 4th of 13 in Arizona
- Wet days83rd driest of 378
- Comfortable days265th most of 341
What to pack for Phoenix in August
- Light, breathable clothing – highs near 105°F and about 5 muggy days
Heating and cooling
August has 0 heating degree days and 910 cooling degree days (base 65°F), 16% of the year's total heating and cooling demand.
Questions
How hot is Phoenix in August?
The normal high is 105°F and the normal low is 84°F. From 1991 to 2020 the hottest August reading was 117°F (most recently on August 14, 2020).
Does it rain a lot in Phoenix in August?
About 5 days in August have at least 0.01 in of precipitation, and the normal total is 0.9 in. The wettest August in 1991-2020 was in 2008 (3.6 in); the driest was in 2002, with no measurable precipitation.
Is August a good time to visit Phoenix?
August ranks 11th of 12 months on our comfort score for Phoenix (34 out of 100). It has almost no comfortable days and about 31 days at 90°F or hotter. The best months are January and February.
Where the numbers come from
- Temperature, rain, frost dates and humidity and wind by hour: Phoenix Sky Harbor Intl Airport (USW00023183), 4.3 mi ESE of the city center, 1,107 ft . NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: Tempe ASU (USC00028499), 8.9 mi E of the city center, 1,167 ft (79 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Phoenix Sky Harbor Intl Airport (722780-23183), 4.3 mi ESE of the city center, 1,113 ft . Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).