Bismarck weather in September: Bismarck, North Dakota: normal highs, lows, rain and records for September
Bismarck in September has a normal high of 73°F and a normal low of 46°F, a daily mean of 60°F, falling from 79°F on the 1st to 67°F by the 30th. Measurable precipitation falls on 7 days in a normal September, 1.72 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 23°C and low of 8°C, 44 mm of precipitation in September.
- NOAA stationBismarck Municipal Airport
- Station IDUSW00024011
- Location46.77°N 100.76°W
- Elevation1,658 ft (505 m)
- From the center3 miles
- Population77,772
- Jan 23° 2°
- Feb 28° 7°
- Mar 41° 19°
- Apr 56° 30°
- May 68° 42°
- Jun 78° 53°
- Jul 85° 58°
- Aug 84° 56°
- Sep 73° 46°
- Oct 57° 33°
- Nov 41° 19°
- Dec 28° 8°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Bismarck in September?
The normal high is 73°F and the normal low 46°F, for a daily mean of 59.7°F. September is 9.9°F cooler than August and 14.9°F warmer than October. September is the 4th warmest month of the year in Bismarck and the 5th wettest. Across the month the normal high falls 12°F, from 79°F on September 1 to 67°F on September 30. From one year to the next September's mean temperature typically moves about 2.7°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 57°F and 62°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 25%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 79°F | 51°F | 25% | 12% |
| September 8 | 77°F | 49°F | 25% | 11% |
| September 15 | 74°F | 46°F | 24% | 11% |
| September 22 | 71°F | 43°F | 24% | 11% |
| September 30 | 67°F | 40°F | 23% | 11% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 79°F | 51°F | 25% | 12% | 13 h 20 min |
| September 2 | 79°F | 51°F | 25% | 12% | 13 h 20 min |
| September 3 | 79°F | 51°F | 25% | 11% | 13 h 20 min |
| September 4 | 78°F | 50°F | 25% | 11% | 13 h 10 min |
| September 5 | 78°F | 50°F | 25% | 11% | 13 h 10 min |
| September 6 | 78°F | 50°F | 25% | 11% | 13 h 10 min |
| September 7 | 77°F | 49°F | 25% | 11% | 13 h |
| September 8 | 77°F | 49°F | 25% | 11% | 13 h |
| September 9 | 76°F | 49°F | 25% | 11% | 13 h |
| September 10 | 76°F | 48°F | 25% | 11% | 12 h 50 min |
| September 11 | 76°F | 48°F | 25% | 11% | 12 h 50 min |
| September 12 | 75°F | 47°F | 25% | 11% | 12 h 50 min |
| September 13 | 75°F | 47°F | 25% | 11% | 12 h 40 min |
| September 14 | 74°F | 47°F | 24% | 11% | 12 h 40 min |
| September 15 | 74°F | 46°F | 24% | 11% | 12 h 40 min |
| September 16 | 74°F | 46°F | 24% | 11% | 12 h 30 min |
| September 17 | 73°F | 45°F | 24% | 11% | 12 h 30 min |
| September 18 | 73°F | 45°F | 24% | 11% | 12 h 30 min |
| September 19 | 72°F | 45°F | 24% | 11% | 12 h 30 min |
| September 20 | 72°F | 44°F | 24% | 11% | 12 h 20 min |
| September 21 | 71°F | 44°F | 24% | 11% | 12 h 20 min |
| September 22 | 71°F | 43°F | 24% | 11% | 12 h 20 min |
| September 23 | 70°F | 43°F | 24% | 11% | 12 h 10 min |
| September 24 | 70°F | 43°F | 24% | 11% | 12 h 10 min |
| September 25 | 69°F | 42°F | 24% | 11% | 12 h 10 min |
| September 26 | 69°F | 42°F | 23% | 11% | 12 h |
| September 27 | 68°F | 41°F | 23% | 11% | 12 h |
| September 28 | 68°F | 41°F | 23% | 11% | 12 h |
| September 29 | 67°F | 40°F | 23% | 11% | 11 h 50 min |
| September 30 | 67°F | 40°F | 23% | 11% | 11 h 50 min |
- Normal high
- 73°FSeptember average
- Normal low
- 46°FSeptember average
- Precipitation
- 1.72 inmonth total
- Days with precipitation
- 70.01 inch or more
- Days at 90°F or more
- 2
- Nights at 32°F or colder
- 2
- Daylight
- 13 h 20 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 19
- Days at 80°F or more
- 10
- Sunshine
- 79%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024011; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Bismarck in September?
On a given September day the chance of 0.01 inch or more is 24% on average, highest around September 1 (25%). In all, 1.72 in falls on 7 days of a normal September.
In a normal September in Bismarck, 2 days reach 90°F and 2 nights fall to freezing.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024011.
How humid and windy is Bismarck in September?
At 3 p.m. the normal temperature is 64°F with 40% relative humidity and a dew point of 40°F; at 6 a.m. it is 44°F with 80% humidity. The wind averages 9.3 mph, most often from the west-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. | 44°F | 38°F | 80% | 7.4 mph | 63% |
| 9 a.m. | 50°F | 40°F | 70% | 9.4 mph | 69% |
| noon | 60°F | 41°F | 48% | 12.5 mph | 59% |
| 3 p.m. | 64°F | 40°F | 40% | 13.3 mph | 66% |
| 6 p.m. | 61°F | 40°F | 47% | 10.4 mph | 60% |
| 9 p.m. | 51°F | 40°F | 65% | 7.8 mph | 74% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024011. 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 September in Bismarck?
The warmest September temperature on Bismarck's official record (since 1874) is 105°F, on September 7, 1931; the coldest is 10°F, on September 30, 1876. The wettest September brought 6.93 in (1977); the snowiest, 5.0 inches (1984).
The September mean against the 1991-2020 normal of 59.7°F: 2021 65.1°F (+5.4), 2022 63.5°F (+3.8), 2023 63.6°F (+3.9), 2024 67.3°F (+7.6), 2025 64.3°F (+4.6), 2026 64.0°F (+4.3). 6 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 65.1°F | +5.4°F | 1.06 in |
| 2022 | 63.5°F | +3.8°F | 0.97 in |
| 2023 | 63.6°F | +3.9°F | 2.99 in |
| 2024 | 67.3°F | +7.6°F | 0.21 in |
| 2025 | 64.3°F | +4.6°F | 4.14 in |
| 2026 | 64.0°F | +4.3°F | 2.49 in |
Source: records: ACIS, NWS threaded record BISthr; recent months: ACIS, station USW00024011. Records and recent months use complete months only.
How does September in Bismarck compare across North Dakota?
Across the 92 places PlainClimate covers in North Dakota, September normal highs run from 65°F in Rolla to 77°F in Beulah; Bismarck's is 73°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Bismarck in August84°F by day, 56°F at night
- Bismarck in October57°F by day, 33°F at night
- Bismarck through the yearEvery month, frost dates, records and recent years
- North Dakota in SeptemberThe statewide normal and the warmest and coolest places
- Beulah: North Dakota's warmest Septembernormal high 77°F