September
Other strong months: July and August
76/100 weather score
United States · 1991–2020
Best time to visit
Bozeman
For Bozeman, September has the most comfortable weather in our climate comparison. Typical daytime highs are 22.6°C, nights average 5.8°C, and rainfall totals about 37 mm. Figures use measured 1991–2020 normals from the nearest eligible NOAA station.
Best all-round monthSeptember
Typical daytime high22.6°C
Typical night-time low5.8°C
September rainfall37 mm
September
Other strong months: August and June
80/100 weather score
Make the answer personal
Choose the weather
that suits you.
Set the daytime temperature and rainfall you are comfortable with. We will show only the months that meet every choice, using the measured 1991–2020 averages below.
1 month fits your choices for Bozeman
The lowest comfort score is 5 out of 100. January, February, November and December share that score. In January, that is mainly because days reach only 1.9°C, 22° below the 24°C the score treats as ideal.
Quick answers
Planning a trip to Bozeman?
These answers come from the same measured monthly climate record shown on this page.
When is the best time to visit Bozeman?
September is the strongest all-round choice in our temperature-and-rainfall comparison, with a typical daytime high of 22.6°C and 37 mm of rain.
What is the hottest month in Bozeman?
July is hottest in this record, with a typical daytime high of 28.5°C and a night-time low of 11.1°C.
Which month has the least rain?
February has the lowest monthly rainfall total at 21 mm.
Is this a weather forecast?
No. These are long-term measured averages from 1991–2020. Check a current forecast before you travel.
Month by month
See how the weather
changes through the year.
The bars combine daytime temperature, night-time temperature and rainfall. The figures are measured historical averages, not a forecast for a particular trip.
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 1.9°C | -9.3°C | 22 mm | 6 | 9 h 03 | 5 | Strong coverage |
| February | 3.3°C | -8.4°C | 21 mm | 5.2 | 10 h 17 | 5 | Strong coverage |
| March | 8.5°C | -4.4°C | 35 mm | 8.2 | 11 h 46 | 9 | Strong coverage |
| April | 13.2°C | -0.7°C | 64 mm | 10.1 | 13 h 27 | 26 | Strong coverage |
| May | 18°C | 3.9°C | 74 mm | 11 | 14 h 53 | 48 | Strong coverage |
| June | 22.8°C | 7.7°C | 83 mm | 11.3 | 15 h 41 | 69 | Strong coverage |
| July | 28.5°C | 11.1°C | 33 mm | 6.4 | 15 h 22 | 75 | Strong coverage |
| August | 28.1°C | 10.1°C | 34 mm | 6.5 | 14 h 07 | 75 | Strong coverage |
| September | 22.6°C | 5.8°C | 37 mm | 6.4 | 12 h 29 | 76 | Strong coverage |
| October | 14.6°C | 0.3°C | 47 mm | 7.2 | 10 h 51 | 37 | Strong coverage |
| November | 6.3°C | -5.4°C | 32 mm | 6.2 | 9 h 25 | 5 | Strong coverage |
| December | 1.4°C | -9.7°C | 27 mm | 6.3 | 8 h 42 | 5 | Strong coverage |
What has changed
Recent daytime highs are
0.6°C warmer in Bozeman.
Each bar shows the difference between the 2011–2025 average daytime high and the 1961–1990 average for the same month at the same station. A blank month does not have enough older observations for a reliable comparison.
Jan
+1.3
Feb
-2.0
Mar
+1.4
Apr
+0.4
May
-0.2
Jun
+0.6
Jul
+1.0
Aug
+0.7
Sep
+2.3
Oct
-0.3
Nov
+1.0
Dec
+1.2
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 18.3°C8 Jan 1896 | -40.0°C13 Jan 2024 | 20 mm28 Jan 1942 | 55 mm1942 · driest 3 mm in 1961 | 132 |
| February | 18.3°C5 Feb 2026 | -41.7°C8 Feb 1936 | 22 mm16 Feb 1942 | 62 mm2003 · driest 1 mm in 1973 | 132 |
| March | 25.6°C20 Mar 2026 | -33.9°C4 Mar 2019 | 31 mm11 Mar 1991 | 91 mm1938 · driest 1 mm in 1911 | 132 |
| April | 28.3°C26 Apr 1897 | -23.3°C1 Apr 1936 | 41 mm6 Apr 2006 | 119 mm2009 · driest 5 mm in 1934 | 134 |
| May | 32.8°C22 May 1892 | -8.9°C1 May 1954 | 68 mm7 May 1988 | 243 mm1908 · driest 9 mm in 1897 | 134 |
| June | 35.6°C30 Jun 1990 | -3.3°C3 Jun 1951 | 58 mm13 Jun 2001 | 203 mm1944 · driest 2 mm in 1919 | 133 |
| July | 40.6°C31 Jul 1892 | 0.0°C14 Jul 1913 | 52 mm3 Jul 1993 | 126 mm1993 · driest 2 mm in 1936 | 132 |
| August | 37.8°C11 Aug 2018 | -3.3°C25 Aug 1910 | 35 mm20 Aug 2021 | 97 mm1964 · driest 1 mm in 2001 | 130 |
| September | 37.2°C3 Sep 2022 | -11.1°C24 Sep 1926 | 43 mm10 Sep 1947 | 141 mm1909 · driest 2 mm in 1904 | 130 |
| October | 31.1°C1 Oct 1992 | -23.3°C30 Oct 1935 | 42 mm15 Oct 1935 | 113 mm1951 · driest 2 mm in 1902 | 131 |
| November | 22.8°C12 Nov 1999 | -32.2°C16 Nov 1959 | 41 mm12 Nov 2009 | 83 mm1947 · driest 0 mm in 1894 | 131 |
| December | 17.8°C1 Dec 2021 | -39.4°C22 Dec 2022 | 32 mm26 Dec 2008 | 72 mm2008 · driest 3 mm in 1986 | 131 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 30 | <1 | 9 |
| February | 0 | 0 | 26 | <1 | 8 |
| March | 0 | 0 | 25 | <1 | 8 |
| April | <1 | 0 | 19 | 2 | 7 |
| May | 4 | <1 | 6 | 2 | 2 |
| June | 11 | 3 | <1 | 3 | <1 |
| July | 26 | 12 | 0 | <1 | 0 |
| August | 25 | 11 | <1 | <1 | 0 |
| September | 12 | 2 | 2 | 1 | <1 |
| October | 2 | <1 | 15 | 1 | 3 |
| November | 0 | 0 | 25 | <1 | 7 |
| December | 0 | 0 | 29 | <1 | 9 |
The best month has moved. On the 1961–1990 numbers the strongest month here was July (scoring 80); on 2011–2025 it is June (82). Both are scored the same way, from the same station — only the climate underneath changed.
| Month | Dry days reaching 20°C | Wet days | Days with heavy rain | Weeks with 3+ wet days | Typical high by year |
|---|---|---|---|---|---|
| January | 0% | 18% | <1% | 14% | -3.7–3.5°C |
| February | 0% | 17% | <1% | 14% | -2.4–6.0°C |
| March | 1% | 23% | 2% | 22% | 2.0–10.2°C |
| April | 12% | 28% | 4% | 34% | 9.4–15.6°C |
| May | 31% | 33% | 8% | 44% | 14.4–20.8°C |
| June | 53% | 34% | 8% | 41% | 18.9–25.3°C |
| July | 78% | 20% | 3% | 17% | 24.8–30.5°C |
| August | 78% | 19% | 3% | 17% | 24.6–29.2°C |
| September | 56% | 21% | 5% | 24% | 17.1–24.2°C |
| October | 21% | 20% | 4% | 19% | 10.2–17.3°C |
| November | <1% | 20% | 2% | 16% | 2.1–9.2°C |
| December | 0% | 18% | 1% | 15% | -2.3–4.3°C |
A dry day reaching 20°C records under 1 mm of rain. A wet day records at least 1 mm, while a heavy-rain day records at least 10 mm. The weekly figure is the share of seven-day periods containing three or more wet days. The final column shows the middle 80% of average daytime highs recorded for that month in individual years; a wider range means conditions have varied more from one year to another.
The evidence behind this page
Where these figures
come from.
- Place identity
- GeoNames 5641727
- NOAA station
- USC00241044 · BOZEMAN MONTANA STATE UNIV
- Station distance
- 2 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 29 usable years
- Daylight
- Calculated from latitude 45.68°, mid-month, sunrise to sunset including refraction. Not a station measurement.
- Important limit
- Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.
Next step
Choose your month.
Then plan the details.
The weather comparison for Bozeman is based on climate evidence, not payments from travel companies. Flight, accommodation and activity links will be clearly labelled when they are added; there are no booking offers on this page today.
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