Climate averages 1991–2020
Billings weather
in September.
A warm, fairly dry month: the 4th warmest and the 8th driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Billings: daytime highs average 23.7°C and nights cool to about 10.4°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 35 mm of rain on roughly 6 days, which makes September a fairly dry month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 35 min on an average September day.
The nearest other city in this atlas is Missoula (439 km away). In September its highs average 22.5°C, 1.3°C cooler than Billings, with 30 mm of rain.
Among the 498 cities listed in the United States, Billings ranks joint 374th of 498 for the warmest September highs and 152nd of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Billings is 3.2°C cooler than that mean.
From September to October, average highs fall by 8.6°C to 15.1°C, and monthly rainfall rises from 35 mm to 46 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Billings climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.3°C-8.8°C | -8.8°C | 22 | 5.7 | 9.19 h |
| February | 3.5°C-7.6°C | -7.6°C | 20 | 6.1 | 10.310 h |
| March | 9.4°C-3.2°C | -3.2°C | 31 | 7.1 | 11.912 h |
| April | 13.9°C1.2°C | 1.2°C | 59 | 10.8 | 13.514 h |
| May | 19.6°C7.0°C | 7.0°C | 65 | 10.7 | 14.915 h |
| June | 24.9°C12.0°C | 12.0°C | 53 | 9.0 | 15.716 h |
| July | 30.7°C16.6°C | 16.6°C | 24 | 4.8 | 15.315 h |
| August | 30.0°C15.8°C | 15.8°C | 18 | 3.9 | 14.114 h |
| September, selected | 23.7°C10.4°C | 10.4°C | 35 | 5.5 | 12.613 h |
| October | 15.1°C3.3°C | 3.3°C | 46 | 7.2 | 11.011 h |
| November | 7.4°C-3.0°C | -3.0°C | 23 | 5.9 | 9.510 h |
| December | 1.8°C-7.5°C | -7.5°C | 20 | 5.5 | 8.79 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Missoula in SeptemberUnited States · 439 kmHigh 22.5°C · Low 9.8°C · 30 mm rain
- Rapid City in SeptemberUnited States · 456 kmHigh 23.3°C · Low 11.2°C · 42 mm rain
- Lethbridge in SeptemberCanada · 542 kmHigh 19.7°C · Low 8.3°C · 37 mm rain
- Ogden in SeptemberUnited States · 579 kmHigh 24.4°C · Low 11.4°C · 32 mm rain
- Regina in SeptemberCanada · 593 kmHigh 18.3°C · Low 8.2°C · 40 mm rain
- Layton in SeptemberUnited States · 595 kmHigh 24.2°C · Low 11.3°C · 30 mm rain
- Bismarck in SeptemberUnited States · 603 kmHigh 21.4°C · Low 10.9°C · 46 mm rain
- Salt Lake City in SeptemberUnited States · 622 kmHigh 25.3°C · Low 12.1°C · 34 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Billings) is explained once on the Billings year overview and on the Sources, method and limits page.