Bismarck, ND weather in August
August in Bismarck: warm, with some rain. Highs 84°F, lows 56°F, rain on about 8 days. This is the peak of the warm season in Bismarck. A good month for most outdoor plans.
- Normal high
- 84°F
- Normal low
- 56°F
- Wet days
- 8
- 2.5 in total
- Muggy days
- 2
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 86°F | 80°F |
| Normal low | 58°F | 52°F |
| Chance of a wet day | 27% | 25% |
| Sunrise / sunset | 6:23 am / 9:15 pm | 7:01 am / 8:25 pm |
| Daylight | 14.9 h | 13.4 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Central Time).
A typical August day
- 6 am58°Fdew point 54°F
- 9 am68°Fdew point 57°F
- Noon77°Fdew point 56°F
- 3 pm81°Fdew point 55°F
- 6 pm80°Fdew point 54°F
- 9 pm69°Fdew point 56°F
NOAA hourly normals (local standard time) from Bismarck (3 mi away); average wind 9 mph; clear or few clouds in 73% of daytime hours, mostly cloudy or overcast in 20%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F9 of 31
- Hot dayshigh 90°F or more7 of 31
- Muggy daysdaily mean dew point 65°F or more2 of 31
- Wet daysat least 0.01 in of rain or melted snow8 of 31
- Notable rainat least 0.10 in4 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 2.5 in; a dry August brings about 1.1 in and a wet one about 3.0 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How August varies from year to year
- Warmest August, 1991-20202003: average high 91°F
- Coolest August2004: average high 78°F
- Wettest August1998: 9.3 in
- Driest August2001: no measurable precipitation
- Highest reading106°F (August 17, 2003)
- Lowest reading34°F (August 31, 1992)
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 | 85°F | 84°F | 73°F |
| Normal low | 58°F | 56°F | 46°F |
| Wet days | 10 | 8 | 7 |
| Comfortable days | 8 | 9 | 15 |
| Daylight | 15.4 h | 14.2 h | 12.6 h |
Highs change by -1°F from July and -11°F into September.
Nearby alternatives in August
- Cooler: Keystone, SD238 mi · high 78°F · 9 wet days
How Bismarck ranks in August
- Normal high241st warmest of 378 cities; 2nd of 4 in North Dakota
- Wet days155th driest of 378
- Comfortable days78th most of 341
What to pack for Bismarck in August
- Layers – afternoons near 84°F but nights near 56°F
- A rain jacket or umbrella – rain on about 8 days
- Sunglasses and sunscreen – about 14.2 hours of daylight and highs near 84°F
Heating and cooling
August has 31 heating degree days and 174 cooling degree days (base 65°F), 2% of the year's total heating and cooling demand.
Questions
How hot is Bismarck in August?
The normal high is 84°F and the normal low is 56°F. From 1991 to 2020 the hottest August reading was 106°F (August 17, 2003).
Does it rain a lot in Bismarck in August?
About 8 days in August have at least 0.01 in of precipitation, and the normal total is 2.5 in. The wettest August in 1991-2020 was in 1998 (9.3 in); the driest was in 2001, with no measurable precipitation.
Is August a good time to visit Bismarck?
August ranks 5th of 12 months on our comfort score for Bismarck (61 out of 100). It has about 9 comfortable days and about 7 days at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth, frost dates, humidity and wind by hour and cloud cover: Bismarck (USW00024011), 2.8 mi SSE of the city center, 1,658 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Bismarck Municipal Airport (727640-24011), 2.2 mi SE of the city center, 1,651 ft . Hourly observations, 1991-2020.