Flagstaff weather in August: Flagstaff, Arizona: normal highs, lows, rain and records for August
Flagstaff in August has a normal high of 79°F and a normal low of 51°F, a daily mean of 65°F, falling from 81°F on the 1st to 78°F by the 31st. Measurable precipitation falls on 13 days in a normal August, 3.04 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 26°C and low of 10°C, 77 mm of precipitation in August.
- NOAA stationFlagstaff Airport
- Station IDUSW00003103
- Location35.14°N 111.67°W
- Elevation7,003 ft (2,135 m)
- Population77,539
- Jan 43° 18°
- Feb 46° 20°
- Mar 52° 24°
- Apr 59° 28°
- May 68° 35°
- Jun 79° 43°
- Jul 82° 51°
- Aug 79° 51°
- Sep 74° 43°
- Oct 64° 32°
- Nov 52° 23°
- Dec 43° 17°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Flagstaff in August?
The normal high is 79°F and the normal low 51°F, for a daily mean of 64.9°F. August is 1.8°F cooler than July and 6.6°F warmer than September. August is the 2nd warmest month of the year in Flagstaff and the wettest. Across the month the normal high falls 3°F, from 81°F on August 1 to 78°F on August 31. From one year to the next August's mean temperature typically moves about 1.8°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 63°F and 67°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 45%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 81°F | 53°F | 44% | 23% |
| August 8 | 80°F | 52°F | 44% | 24% |
| August 15 | 79°F | 51°F | 43% | 23% |
| August 22 | 79°F | 50°F | 41% | 22% |
| August 31 | 78°F | 48°F | 36% | 20% |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 1, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 81°F | 53°F | 44% | 23% | 14 h |
| August 2 | 81°F | 53°F | 44% | 24% | 13 h 50 min |
| August 3 | 81°F | 53°F | 45% | 24% | 13 h 50 min |
| August 4 | 80°F | 52°F | 45% | 24% | 13 h 50 min |
| August 5 | 80°F | 52°F | 45% | 24% | 13 h 50 min |
| August 6 | 80°F | 52°F | 45% | 24% | 13 h 50 min |
| August 7 | 80°F | 52°F | 44% | 24% | 13 h 50 min |
| August 8 | 80°F | 52°F | 44% | 24% | 13 h 40 min |
| August 9 | 80°F | 52°F | 44% | 24% | 13 h 40 min |
| August 10 | 80°F | 52°F | 44% | 24% | 13 h 40 min |
| August 11 | 80°F | 52°F | 44% | 24% | 13 h 40 min |
| August 12 | 80°F | 52°F | 44% | 23% | 13 h 40 min |
| August 13 | 80°F | 51°F | 44% | 23% | 13 h 40 min |
| August 14 | 80°F | 51°F | 44% | 23% | 13 h 30 min |
| August 15 | 79°F | 51°F | 43% | 23% | 13 h 30 min |
| August 16 | 79°F | 51°F | 43% | 23% | 13 h 30 min |
| August 17 | 79°F | 51°F | 43% | 23% | 13 h 30 min |
| August 18 | 79°F | 51°F | 42% | 23% | 13 h 30 min |
| August 19 | 79°F | 50°F | 42% | 23% | 13 h 20 min |
| August 20 | 79°F | 50°F | 42% | 23% | 13 h 20 min |
| August 21 | 79°F | 50°F | 42% | 22% | 13 h 20 min |
| August 22 | 79°F | 50°F | 41% | 22% | 13 h 20 min |
| August 23 | 79°F | 50°F | 41% | 22% | 13 h 20 min |
| August 24 | 79°F | 49°F | 40% | 22% | 13 h 10 min |
| August 25 | 79°F | 49°F | 40% | 22% | 13 h 10 min |
| August 26 | 78°F | 49°F | 39% | 21% | 13 h 10 min |
| August 27 | 78°F | 49°F | 39% | 21% | 13 h 10 min |
| August 28 | 78°F | 48°F | 38% | 21% | 13 h 10 min |
| August 29 | 78°F | 48°F | 38% | 21% | 13 h |
| August 30 | 78°F | 48°F | 37% | 20% | 13 h |
| August 31 | 78°F | 48°F | 36% | 20% | 13 h |
- Normal high
- 79°FAugust average
- Normal low
- 51°FAugust average
- Precipitation
- 3.04 inmonth total
- Days with precipitation
- 130.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 14 h to 13 hAugust 1 to August 31
- Days at 70°F or more
- 30
- Days at 80°F or more
- 15
- Sunshine
- 82%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00003103; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Flagstaff in August?
On a given August day the chance of 0.01 inch or more is 42% on average, highest around August 3 (45%). In all, 3.04 in falls on 13 days of a normal August, 1 of them with an inch or more.
In a normal August in Flagstaff, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00003103.
What are the records for August in Flagstaff?
The warmest August temperature on Flagstaff's official record (since 1898) is 93°F, on August 2, 1902; the coldest is 24°F, on August 23, 1968. The wettest August brought 8.77 in (1904).
The August mean against the 1991-2020 normal of 64.9°F: 2021 65.0°F (+0.1), 2022 66.0°F (+1.1), 2023 66.9°F (+2.0), 2024 68.1°F (+3.2), 2025 67.9°F (+3.0), 2026 68.8°F (+3.9). 6 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 65.0°F | +0.1°F | 3.51 in |
| 2022 | 66.0°F | +1.1°F | 5.46 in |
| 2023 | 66.9°F | +2.0°F | 3.24 in |
| 2024 | 68.1°F | +3.2°F | 2.69 in |
| 2025 | 67.9°F | +3.0°F | 1.10 in |
| 2026 | 68.8°F | +3.9°F | 1.55 in |
Source: records: ACIS, NWS threaded record FLGthr; recent months: ACIS, station USW00003103. Records and recent months use complete months only.
How does August in Flagstaff compare across Arizona?
Across the 97 places PlainClimate covers in Arizona, August normal highs run from 73°F in Greer to 109°F in Bullhead City; Flagstaff's is 79°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.