Santa Rosa Weather in September
Average highs run from 101°F on September 1 to 94°F on September 30, and lows from 73°F to 61°F. Normal precipitation for the month is 0.96 in over about 4 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
- 98°F
- Average low
- 68°F
- Precipitation
- 0.96 in
- Record high
- 114°FSep 5, 2020
- Record low
- 52°FSep 24, 2007
- Chance of a freeze
- 0%
- Days of 90°F or more
- 27.5
- Daylight
- 12 h 49 min to 11 h 52 min
- Cloud cover
- 30%
- Humidity
- 37%
- Dew point
- 51°F
- Wind
- 6.5 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Sep 1 | 101°F | 73°F | 109°F 2017 | 68°F 1999 | 16% |
| Sep 2 | 101°F | 72°F | 107°F 2002 | 67°F 1992 | 16% |
| Sep 3 | 101°F | 72°F | 108°F 2010 | 67°F 2000 | 16% |
| Sep 4 | 101°F | 72°F | 112°F 2020 | 68°F 2000 | 16% |
| Sep 5 | 101°F | 72°F | 114°F 2020 | 67°F 1992 | 16% |
| Sep 6 | 100°F | 71°F | 113°F 2020 | 65°F 2004 | 15% |
| Sep 7 | 100°F | 71°F | 109°F 2022 | 66°F 2006 | 15% |
| Sep 8 | 100°F | 71°F | 107°F 2000 | 65°F 1999 | 15% |
| Sep 9 | 100°F | 70°F | 109°F 2023 | 65°F 1989 | 15% |
| Sep 10 | 100°F | 70°F | 110°F 2023 | 62°F 2010 | 14% |
| Sep 11 | 99°F | 70°F | 109°F 2023 | 62°F 2020 | 14% |
| Sep 12 | 99°F | 69°F | 108°F 1990 | 63°F 2019 | 14% |
| Sep 13 | 99°F | 69°F | 109°F 2000 | 62°F 1988 | 13% |
| Sep 14 | 99°F | 69°F | 111°F 2000 | 61°F 1988 | 13% |
| Sep 15 | 98°F | 68°F | 111°F 2000 | 62°F 1994 | 12% |
| Sep 16 | 98°F | 68°F | 107°F 2018 | 58°F 2019 | 12% |
| Sep 17 | 98°F | 67°F | 107°F 2020 | 63°F 2006 | 11% |
| Sep 18 | 98°F | 67°F | 107°F 2020 | 59°F 1993 | 11% |
| Sep 19 | 97°F | 66°F | 104°F 1997 | 58°F 1993 | 11% |
| Sep 20 | 97°F | 66°F | 107°F 2010 | 54°F 2007 | 10% |
| Sep 21 | 97°F | 66°F | 107°F 2010 | 55°F 2019 | 10% |
| Sep 22 | 96°F | 65°F | 107°F 1989 | 57°F 2004 | 9% |
| Sep 23 | 96°F | 65°F | 108°F 2001 | 54°F 2019 | 9% |
| Sep 24 | 96°F | 64°F | 106°F 2001 | 52°F 2007 | 9% |
| Sep 25 | 95°F | 64°F | 109°F 2024 | 52°F 2017 | 8% |
| Sep 26 | 95°F | 63°F | 108°F 2024 | 57°F 2017 | 8% |
| Sep 27 | 95°F | 63°F | 109°F 2024 | 59°F 2017 | 8% |
| Sep 28 | 94°F | 62°F | 111°F 2024 | 57°F 2013 | 8% |
| Sep 29 | 94°F | 62°F | 109°F 2024 | 60°F 2013 | 7% |
| Sep 30 | 94°F | 61°F | 107°F 2010 | 52°F 2004 | 7% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (MST).
- September 1
- sunrise 6:03 AM, sunset 6:52 PM
- September 30
- sunrise 6:22 AM, sunset 6:14 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00020404 (Arizona City), public domain. Records: NOAA GHCN-Daily, station USC00026513, 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 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.