Great Falls weather in August: Great Falls, Montana: normal highs, lows, rain and records for August
Great Falls in August has a normal high of 83°F and a normal low of 50°F, a daily mean of 67°F, falling from 87°F on the 1st to 78°F by the 31st. Measurable precipitation falls on 7 days in a normal August, 1.22 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 28°C and low of 10°C, 31 mm of precipitation and 1 cm of snow in August.
- NOAA stationGreat Falls Airport
- Station IDUSW00024143
- Location47.47°N 111.38°W
- Elevation3,664 ft (1,117 m)
- From the center4 miles
- Population60,013
- Jan 35° 15°
- Feb 37° 15°
- Mar 46° 22°
- Apr 55° 30°
- May 65° 38°
- Jun 73° 46°
- Jul 84° 51°
- Aug 83° 50°
- Sep 72° 43°
- Oct 57° 33°
- Nov 44° 24°
- Dec 36° 16°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Great Falls in August?
The normal high is 83°F and the normal low 50°F, for a daily mean of 66.7°F. August is 1.2°F cooler than July and 9.5°F warmer than September. August is the 2nd warmest month of the year in Great Falls and the 6th wettest. Across the month the normal high falls 9°F, from 87°F on August 1 to 78°F on August 31. From one year to the next August's mean temperature typically moves about 2.8°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 64°F and 70°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 23%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 87°F | 53°F | 21% | 9% |
| August 8 | 86°F | 52°F | 21% | 9% |
| August 15 | 84°F | 51°F | 21% | 10% |
| August 22 | 81°F | 49°F | 22% | 10% |
| August 31 | 78°F | 47°F | 23% | 11% |
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 | 87°F | 53°F | 21% | 9% | 15 h |
| August 2 | 87°F | 53°F | 21% | 9% | 15 h |
| August 3 | 87°F | 53°F | 21% | 9% | 14 h 50 min |
| August 4 | 87°F | 53°F | 21% | 9% | 14 h 50 min |
| August 5 | 87°F | 53°F | 21% | 9% | 14 h 50 min |
| August 6 | 86°F | 52°F | 21% | 9% | 14 h 50 min |
| August 7 | 86°F | 52°F | 21% | 9% | 14 h 40 min |
| August 8 | 86°F | 52°F | 21% | 9% | 14 h 40 min |
| August 9 | 86°F | 52°F | 21% | 9% | 14 h 40 min |
| August 10 | 85°F | 52°F | 21% | 10% | 14 h 30 min |
| August 11 | 85°F | 52°F | 21% | 10% | 14 h 30 min |
| August 12 | 85°F | 51°F | 21% | 10% | 14 h 30 min |
| August 13 | 85°F | 51°F | 21% | 10% | 14 h 30 min |
| August 14 | 84°F | 51°F | 21% | 10% | 14 h 20 min |
| August 15 | 84°F | 51°F | 21% | 10% | 14 h 20 min |
| August 16 | 84°F | 51°F | 21% | 10% | 14 h 20 min |
| August 17 | 83°F | 50°F | 21% | 10% | 14 h 10 min |
| August 18 | 83°F | 50°F | 22% | 10% | 14 h 10 min |
| August 19 | 83°F | 50°F | 22% | 10% | 14 h 10 min |
| August 20 | 82°F | 50°F | 22% | 10% | 14 h |
| August 21 | 82°F | 49°F | 22% | 10% | 14 h |
| August 22 | 81°F | 49°F | 22% | 10% | 14 h |
| August 23 | 81°F | 49°F | 22% | 10% | 13 h 50 min |
| August 24 | 81°F | 49°F | 22% | 11% | 13 h 50 min |
| August 25 | 80°F | 48°F | 22% | 11% | 13 h 50 min |
| August 26 | 80°F | 48°F | 22% | 11% | 13 h 50 min |
| August 27 | 79°F | 48°F | 23% | 11% | 13 h 40 min |
| August 28 | 79°F | 48°F | 23% | 11% | 13 h 40 min |
| August 29 | 79°F | 47°F | 23% | 11% | 13 h 40 min |
| August 30 | 78°F | 47°F | 23% | 11% | 13 h 30 min |
| August 31 | 78°F | 47°F | 23% | 11% | 13 h 30 min |
- Normal high
- 83°FAugust average
- Normal low
- 50°FAugust average
- Precipitation
- 1.22 inmonth total
- Days with precipitation
- 70.01 inch or more
- Snowfall
- 0.3 inmonth total
- Days at 90°F or more
- 9
- Daylight
- 15 h to 13 h 30 minAugust 1 to August 31
- Days at 70°F or more
- 28
- Days at 80°F or more
- 22
- Sunshine
- 85%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024143; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Great Falls in August?
On a given August day the chance of 0.01 inch or more is 21% on average, highest around August 30 (23%). In all, 1.22 in falls on 7 days of a normal August.
In a normal August in Great Falls, 9 days reach 90°F and snowfall averages 0.3 inches.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024143.
How humid and windy is Great Falls in August?
At 3 p.m. the normal temperature is 77°F with 23% relative humidity and a dew point of 37°F; at 6 a.m. it is 51°F with 64% humidity. The wind averages 9.2 mph, most often from the west in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 51°F | 39°F | 64% | 7.7 mph | 74% |
| 9 a.m. | 64°F | 41°F | 43% | 9.4 mph | 79% |
| noon | 73°F | 39°F | 29% | 10.1 mph | 77% |
| 3 p.m. | 77°F | 37°F | 23% | 11.7 mph | 73% |
| 6 p.m. | 73°F | 37°F | 27% | 10.6 mph | 73% |
| 9 p.m. | 62°F | 39°F | 42% | 9.0 mph | 73% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024143. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for August in Great Falls?
The warmest August temperature on Great Falls's official record (since 1891) is 106°F, on August 5, 1961; the coldest is 30°F, on August 24, 1992. The wettest August brought 5.34 in (1933); the snowiest, 8.3 inches (1992).
The August mean against the 1991-2020 normal of 66.7°F: 2021 66.1°F (−0.6), 2022 72.3°F (+5.6), 2023 69.0°F (+2.3), 2024 67.1°F (+0.4), 2025 68.2°F (+1.5), 2026 66.7°F (at normal). 4 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 66.1°F | −0.6°F | 2.18 in |
| 2022 | 72.3°F | +5.6°F | 0.40 in |
| 2023 | 69.0°F | +2.3°F | 0.63 in |
| 2024 | 67.1°F | +0.4°F | 0.66 in |
| 2025 | 68.2°F | +1.5°F | 0.61 in |
| 2026 | 66.7°F | at normal | 1.44 in |
Source: records: ACIS, NWS threaded record GTFthr; recent months: ACIS, station USW00024143. Records and recent months use complete months only.
How does August in Great Falls compare across Montana?
Across the 141 places PlainClimate covers in Montana, August normal highs run from 71°F in Cooke City to 90°F in Hardin; Great Falls's is 83°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.