Mountain View Weather in September
Average highs run from 84°F on September 1 to 73°F on September 30, and lows from 51°F to 39°F. Normal precipitation for the month is 1.34 in over about 7 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
- 79°F
- Average low
- 45°F
- Precipitation
- 1.34 in
- Snowfall
- 1.0 in
- Record high
- 102°FSep 3, 2019
- Record low
- 18°FSep 29, 1985
- Chance of a freeze
- 35%
- Days of 90°F or more
- 3.3
- Daylight
- 13 h 03 min to 11 h 48 min
- Cloud cover
- 46%
- Humidity
- 43%
- Dew point
- 37°F
- Wind
- 7.2 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 | 84°F | 51°F | 98°F 2023 | 46°F 2005 | 24% | 1% |
| Sep 2 | 84°F | 50°F | 101°F 2019 | 45°F 1986 | 24% | 1% |
| Sep 3 | 83°F | 50°F | 102°F 2019 | 42°F 2006 | 24% | 1% |
| Sep 4 | 83°F | 50°F | 100°F 2017 | 34°F 1988 | 24% | 1% |
| Sep 5 | 83°F | 49°F | 99°F 2002 | 44°F 1988 | 24% | 1% |
| Sep 6 | 83°F | 49°F | 101°F 2020 | 42°F 2025 | 24% | 1% |
| Sep 7 | 82°F | 49°F | 101°F 2022 | 41°F 2010 | 24% | 1% |
| Sep 8 | 82°F | 48°F | 100°F 2022 | 37°F 2001 | 23% | 1% |
| Sep 9 | 82°F | 48°F | 102°F 2022 | 38°F 2001 | 23% | 1% |
| Sep 10 | 81°F | 48°F | 98°F 2021 | 40°F 1989 | 23% | 1% |
| Sep 11 | 81°F | 47°F | 101°F 2021 | 36°F 1989 | 23% | 1% |
| Sep 12 | 81°F | 47°F | 101°F 1990 | 32°F 1989 | 23% | 1% |
| Sep 13 | 80°F | 46°F | 99°F 1990 | 31°F 1987 | 23% | 1% |
| Sep 14 | 80°F | 46°F | 98°F 2026 | 30°F 1993 | 23% | 1% |
| Sep 15 | 80°F | 46°F | 94°F 1990 | 35°F 1988 | 23% | 2% |
| Sep 16 | 79°F | 45°F | 98°F 2000 | 36°F 1987 | 23% | 2% |
| Sep 17 | 79°F | 45°F | 96°F 2021 | 41°F 1988 | 22% | 2% |
| Sep 18 | 78°F | 44°F | 93°F 2004 | 35°F 2003 | 22% | 2% |
| Sep 19 | 78°F | 44°F | 96°F 2021 | 31°F 1988 | 22% | 2% |
| Sep 20 | 78°F | 44°F | 95°F 2022 | 34°F 2003 | 22% | 2% |
| Sep 21 | 77°F | 43°F | 96°F 2022 | 28°F 1995 | 22% | 2% |
| Sep 22 | 77°F | 43°F | 94°F 2010 | 26°F 1995 | 22% | 2% |
| Sep 23 | 76°F | 42°F | 88°F 2007 | 26°F 1995 | 22% | 2% |
| Sep 24 | 76°F | 42°F | 90°F 2003 | 27°F 1985 | 22% | 3% |
| Sep 25 | 75°F | 41°F | 90°F 2001 | 30°F 1984 | 21% | 3% |
| Sep 26 | 75°F | 41°F | 92°F 2001 | 29°F 1985 | 21% | 3% |
| Sep 27 | 74°F | 41°F | 96°F 2024 | 29°F 1996 | 21% | 3% |
| Sep 28 | 74°F | 40°F | 91°F 2011 | 20°F 1985 | 21% | 3% |
| Sep 29 | 73°F | 40°F | 92°F 2024 | 18°F 1985 | 21% | 3% |
| Sep 30 | 73°F | 39°F | 95°F 2024 | 21°F 1985 | 20% | 3% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MDT).
- September 1
- sunrise 6:28 AM, sunset 7:31 PM
- September 30
- sunrise 6:56 AM, sunset 6:44 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00058995 (Wheat Ridge 2), public domain. Records: NOAA GHCN-Daily, station USC00055984, 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.