Helena weather in August: Helena, Montana: normal highs, lows, rain and records for August
Helena in August has a normal high of 85°F and a normal low of 53°F, a daily mean of 69°F, falling from 89°F on the 1st to 80°F by the 31st. Measurable precipitation falls on 6 days in a normal August, 1.04 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 29°C and low of 12°C, 26 mm of precipitation and 1 cm of snow in August.
- NOAA stationHelena Regional Airport
- Station IDUSW00024144
- Location46.61°N 111.96°W
- Elevation3,828 ft (1,167 m)
- From the center3 miles
- Population34,729
- Jan 32° 14°
- Feb 37° 17°
- Mar 48° 25°
- Apr 57° 32°
- May 66° 42°
- Jun 75° 49°
- Jul 86° 55°
- Aug 85° 53°
- Sep 73° 45°
- Oct 58° 34°
- Nov 43° 23°
- Dec 33° 14°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Helena in August?
The normal high is 85°F and the normal low 53°F, for a daily mean of 68.8°F. August is 1.8°F cooler than July and 9.9°F warmer than September. August is the 2nd warmest month of the year in Helena and the 4th wettest. Across the month the normal high falls 9°F, from 89°F on August 1 to 80°F on August 31. From one year to the next August's mean temperature typically moves about 2.7°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 66°F and 72°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 21%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 89°F | 56°F | 21% | 10% |
| August 8 | 87°F | 55°F | 20% | 10% |
| August 15 | 85°F | 53°F | 20% | 10% |
| August 22 | 83°F | 51°F | 20% | 10% |
| August 31 | 80°F | 49°F | 20% | 10% |
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 | 89°F | 56°F | 21% | 10% | 14 h 50 min |
| August 2 | 88°F | 56°F | 21% | 10% | 14 h 50 min |
| August 3 | 88°F | 56°F | 21% | 10% | 14 h 50 min |
| August 4 | 88°F | 56°F | 21% | 10% | 14 h 50 min |
| August 5 | 88°F | 56°F | 21% | 10% | 14 h 40 min |
| August 6 | 88°F | 56°F | 21% | 10% | 14 h 40 min |
| August 7 | 88°F | 55°F | 21% | 10% | 14 h 40 min |
| August 8 | 87°F | 55°F | 20% | 10% | 14 h 40 min |
| August 9 | 87°F | 55°F | 20% | 10% | 14 h 30 min |
| August 10 | 87°F | 55°F | 20% | 10% | 14 h 30 min |
| August 11 | 87°F | 54°F | 20% | 10% | 14 h 30 min |
| August 12 | 86°F | 54°F | 20% | 10% | 14 h 20 min |
| August 13 | 86°F | 54°F | 20% | 10% | 14 h 20 min |
| August 14 | 86°F | 54°F | 20% | 10% | 14 h 20 min |
| August 15 | 85°F | 53°F | 20% | 10% | 14 h 20 min |
| August 16 | 85°F | 53°F | 20% | 10% | 14 h 10 min |
| August 17 | 85°F | 53°F | 20% | 10% | 14 h 10 min |
| August 18 | 84°F | 53°F | 20% | 10% | 14 h 10 min |
| August 19 | 84°F | 52°F | 20% | 10% | 14 h |
| August 20 | 84°F | 52°F | 20% | 10% | 14 h |
| August 21 | 83°F | 52°F | 20% | 10% | 14 h |
| August 22 | 83°F | 51°F | 20% | 10% | 13 h 50 min |
| August 23 | 82°F | 51°F | 20% | 10% | 13 h 50 min |
| August 24 | 82°F | 51°F | 20% | 10% | 13 h 50 min |
| August 25 | 82°F | 51°F | 20% | 10% | 13 h 50 min |
| August 26 | 81°F | 50°F | 20% | 10% | 13 h 40 min |
| August 27 | 81°F | 50°F | 20% | 10% | 13 h 40 min |
| August 28 | 81°F | 50°F | 20% | 10% | 13 h 40 min |
| August 29 | 80°F | 49°F | 20% | 10% | 13 h 30 min |
| August 30 | 80°F | 49°F | 20% | 10% | 13 h 30 min |
| August 31 | 80°F | 49°F | 20% | 10% | 13 h 30 min |
- Normal high
- 85°FAugust average
- Normal low
- 53°FAugust average
- Precipitation
- 1.04 inmonth total
- Days with precipitation
- 60.01 inch or more
- Snowfall
- 0.3 inmonth total
- Days at 90°F or more
- 11
- Daylight
- 14 h 50 min to 13 h 30 minAugust 1 to August 31
- Days at 70°F or more
- 29
- Days at 80°F or more
- 24
- Sunshine
- 84%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024144; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Helena in August?
On a given August day the chance of 0.01 inch or more is 20% on average, highest around August 1 (21%). In all, 1.04 in falls on 6 days of a normal August.
In a normal August in Helena, 11 days reach 90°F and snowfall averages 0.3 inches.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024144.
How humid and windy is Helena in August?
At 3 p.m. the normal temperature is 78°F with 24% relative humidity and a dew point of 39°F; at 6 a.m. it is 52°F with 64% humidity. The wind averages 6.4 mph, most often from the northwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 52°F | 40°F | 64% | 3.1 mph | 78% |
| 9 a.m. | 61°F | 42°F | 49% | 3.9 mph | 80% |
| noon | 73°F | 41°F | 32% | 7.0 mph | 79% |
| 3 p.m. | 78°F | 39°F | 24% | 10.5 mph | 77% |
| 6 p.m. | 76°F | 39°F | 26% | 10.0 mph | 76% |
| 9 p.m. | 65°F | 40°F | 39% | 6.7 mph | 78% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024144. 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 Helena?
The warmest August temperature on Helena's official record (since 1880) is 105°F, on August 24, 1969; the coldest is 28°F, on August 25, 1992. The wettest August brought 4.23 in (1974); the snowiest, 6.2 inches (1992).
The August mean against the 1991-2020 normal of 68.8°F: 2021 68.8°F (at normal), 2022 75.3°F (+6.5), 2023 72.3°F (+3.5), 2024 69.8°F (+1.0), 2025 69.7°F (+0.9), 2026 69.8°F (+1.0). 5 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 68.8°F | at normal | 1.98 in |
| 2022 | 75.3°F | +6.5°F | 0.48 in |
| 2023 | 72.3°F | +3.5°F | 0.50 in |
| 2024 | 69.8°F | +1.0°F | 0.76 in |
| 2025 | 69.7°F | +0.9°F | 2.02 in |
| 2026 | 69.8°F | +1.0°F | 1.34 in |
Source: records: ACIS, NWS threaded record HLNthr; recent months: ACIS, station USW00024144. Records and recent months use complete months only.
How does August in Helena 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; Helena's is 85°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.