Larimer County Weather in September
Average highs run from 75°F on September 1 to 64°F on September 30, and lows from 52°F to 41°F. Normal precipitation for the month is 1.88 in over about 8 wet days.
September day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 70°F
- Average low
- 47°F
- Precipitation
- 1.88 in
- Snowfall
- 3.3 in
- Record high
- 103°FSep 3, 2019
- Record low
- 25°FSep 22, 1995
- Chance of a freeze
- 57%
- Daylight
- 13 h 05 min to 11 h 47 min
- Cloud cover
- 54%
- Humidity
- 52%
- Dew point
- 31°F
- Wind
- 6.0 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Sep 1 | 75°F | 52°F | 99°F 2011 | 43°F 2005 | 32% | 1% |
| Sep 2 | 75°F | 52°F | 98°F 2019 | 41°F 2005 | 32% | 1% |
| Sep 3 | 74°F | 51°F | 103°F 2019 | 36°F 1993 | 31% | 1% |
| Sep 4 | 74°F | 51°F | 100°F 2017 | 38°F 2006 | 31% | 1% |
| Sep 5 | 74°F | 51°F | 96°F 2026 | 42°F 2006 | 31% | 1% |
| Sep 6 | 74°F | 51°F | 100°F 2019 | 39°F 2025 | 31% | 1% |
| Sep 7 | 73°F | 50°F | 100°F 2022 | 37°F 2010 | 30% | 2% |
| Sep 8 | 73°F | 50°F | 97°F 2022 | 35°F 2010 | 30% | 2% |
| Sep 9 | 73°F | 50°F | 97°F 2022 | 31°F 2020 | 30% | 2% |
| Sep 10 | 73°F | 49°F | 97°F 2021 | 32°F 2020 | 30% | 2% |
| Sep 11 | 72°F | 49°F | 97°F 2021 | 35°F 1989 | 29% | 2% |
| Sep 12 | 72°F | 49°F | 97°F 2021 | 33°F 1989 | 29% | 2% |
| Sep 13 | 71°F | 48°F | 96°F 1990 | 29°F 2014 | 29% | 2% |
| Sep 14 | 71°F | 48°F | 96°F 2018 | 27°F 1993 | 28% | 3% |
| Sep 15 | 71°F | 48°F | 93°F 2018 | 36°F 1993 | 28% | 3% |
| Sep 16 | 70°F | 47°F | 96°F 2000 | 37°F 2005 | 28% | 3% |
| Sep 17 | 70°F | 47°F | 94°F 2018 | 32°F 2006 | 28% | 3% |
| Sep 18 | 70°F | 46°F | 93°F 2018 | 31°F 2006 | 27% | 3% |
| Sep 19 | 69°F | 46°F | 91°F 2004 | 33°F 1991 | 27% | 4% |
| Sep 20 | 69°F | 46°F | 93°F 2022 | 32°F 1995 | 27% | 4% |
| Sep 21 | 68°F | 45°F | 91°F 2010 | 31°F 1995 | 26% | 4% |
| Sep 22 | 68°F | 45°F | 91°F 2007 | 25°F 1995 | 26% | 4% |
| Sep 23 | 67°F | 44°F | 88°F 1992 | 32°F 1991 | 26% | 4% |
| Sep 24 | 67°F | 44°F | 90°F 2018 | 29°F 2000 | 26% | 5% |
| Sep 25 | 66°F | 43°F | 90°F 2020 | 29°F 2000 | 25% | 5% |
| Sep 26 | 66°F | 43°F | 89°F 2011 | 32°F 1996 | 25% | 5% |
| Sep 27 | 65°F | 43°F | 94°F 2024 | 25°F 1996 | 25% | 5% |
| Sep 28 | 65°F | 42°F | 91°F 2015 | 31°F 1999 | 25% | 6% |
| Sep 29 | 65°F | 42°F | 91°F 2011 | 27°F 1999 | 24% | 6% |
| Sep 30 | 64°F | 41°F | 90°F 2024 | 32°F 2005 | 24% | 6% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MDT).
- September 1
- sunrise 6:29 AM, sunset 7:34 PM
- September 30
- sunrise 6:58 AM, sunset 6:45 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00051060 (Buckhorn Mtn 1 E), public domain. Records: NOAA GHCN-Daily, station USC00055236, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.