Mountain View Weather in September
Average highs run from 91°F on September 1 to 81°F on September 30, and lows from 68°F to 55°F.
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
- 86°F
- Average low
- 62°F
- Record high
- 110°FSep 4, 2000
- Record low
- 31°FSep 30, 1984
- Chance of a freeze
- 0%
- Days of 90°F or more
- 10.9
- Daylight
- 12 h 54 min to 11 h 51 min
- Cloud cover
- 44%
- Humidity
- 61%
- Dew point
- 58°F
- Wind
- 9.8 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 | 91°F | 68°F | 108°F 1947 | 48°F 1956 | 0% | |
| Sep 2 | 90°F | 68°F | 108°F 2000 | 50°F 1952 | 0% | |
| Sep 3 | 90°F | 67°F | 109°F 2000 | 48°F 1974 | 0% | |
| Sep 4 | 90°F | 67°F | 110°F 2000 | 49°F 1953 | 0% | |
| Sep 5 | 89°F | 67°F | 108°F 1998 | 50°F 1953 | 0% | |
| Sep 6 | 89°F | 66°F | 106°F 1947 | 49°F 2011 | 0% | |
| Sep 7 | 89°F | 66°F | 108°F 2023 | 46°F 1950 | 0% | |
| Sep 8 | 88°F | 66°F | 109°F 2023 | 48°F 1950 | 0% | |
| Sep 9 | 88°F | 65°F | 107°F 1922 | 48°F 2004 | 0% | |
| Sep 10 | 88°F | 65°F | 104°F 2000 | 46°F 1962 | 0% | |
| Sep 11 | 87°F | 64°F | 106°F 2000 | 47°F 1960 | 0% | |
| Sep 12 | 87°F | 64°F | 107°F 2026 | 43°F 1947 | 0% | |
| Sep 13 | 87°F | 64°F | 107°F 2011 | 44°F 1947 | 0% | |
| Sep 14 | 86°F | 63°F | 103°F 1918 | 40°F 1947 | 0% | |
| Sep 15 | 86°F | 63°F | 104°F 1956 | 40°F 1947 | 0% | |
| Sep 16 | 86°F | 62°F | 104°F 1956 | 45°F 1916 | 0% | |
| Sep 17 | 85°F | 62°F | 101°F 1931 | 44°F 1981 | 0% | |
| Sep 18 | 85°F | 61°F | 102°F 1952 | 44°F 1981 | 0% | |
| Sep 19 | 85°F | 61°F | 102°F 2024 | 47°F 2003 | 0% | |
| Sep 20 | 84°F | 60°F | 102°F 1953 | 43°F 1918 | 0% | |
| Sep 21 | 84°F | 60°F | 103°F 1977 | 36°F 1983 | 0% | |
| Sep 22 | 84°F | 59°F | 102°F 1926 | 41°F 1912 | 0% | |
| Sep 23 | 83°F | 59°F | 103°F 2023 | 39°F 1947 | 0% | |
| Sep 24 | 83°F | 58°F | 99°F 1998 | 35°F 1989 | 0% | |
| Sep 25 | 83°F | 58°F | 98°F 1930 | 40°F 2000 | 0% | |
| Sep 26 | 82°F | 57°F | 101°F 1953 | 37°F 2000 | 0% | |
| Sep 27 | 82°F | 57°F | 102°F 1953 | 35°F 1942 | 0% | |
| Sep 28 | 81°F | 56°F | 106°F 1953 | 39°F 1918 | 0% | |
| Sep 29 | 81°F | 56°F | 99°F 1998 | 34°F 1936 | 0% | |
| Sep 30 | 81°F | 55°F | 106°F 1977 | 31°F 1984 | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 7:08 AM, sunset 8:02 PM
- September 30
- sunrise 7:29 AM, sunset 7:20 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00341504 (Carnegie 5 Ne), public domain. Records: NOAA GHCN-Daily, station USW00093986, 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.