Santa Clara County Weather in September
Average highs run from 77°F on September 1 to 71°F on September 30, and lows from 63°F to 57°F. Normal precipitation for the month is 0.17 in over about 2 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
- 75°F
- Average low
- 60°F
- Precipitation
- 0.17 in
- Record high
- 106°FSep 7, 1904
- Record low
- 35°FSep 23, 1903
- Chance of a freeze
- 0%
- Daylight
- 12 h 57 min to 11 h 49 min
- Cloud cover
- 16%
- Humidity
- 48%
- Dew point
- 45°F
- Wind
- 7.4 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 | 77°F | 63°F | 101°F 1950 | 44°F 1895 | 3% | 0% |
| Sep 2 | 77°F | 63°F | 102°F 1950 | 42°F 1895 | 3% | 0% |
| Sep 3 | 77°F | 63°F | 99°F 1950 | 45°F 1919 | 4% | 0% |
| Sep 4 | 77°F | 63°F | 98°F 1950 | 43°F 1914 | 4% | 0% |
| Sep 5 | 77°F | 62°F | 98°F 1923 | 40°F 1894 | 4% | 0% |
| Sep 6 | 77°F | 62°F | 100°F 1923 | 42°F 1895 | 4% | 0% |
| Sep 7 | 76°F | 62°F | 106°F 1904 | 44°F 1911 | 4% | 0% |
| Sep 8 | 76°F | 62°F | 100°F 1904 | 42°F 1914 | 4% | 0% |
| Sep 9 | 76°F | 62°F | 106°F 1944 | 43°F 1928 | 4% | 0% |
| Sep 10 | 76°F | 62°F | 98°F 1903 | 42°F 1893 | 5% | 0% |
| Sep 11 | 76°F | 61°F | 100°F 1979 | 44°F 1896 | 5% | 0% |
| Sep 12 | 76°F | 61°F | 101°F 1979 | 43°F 1894 | 5% | 0% |
| Sep 13 | 75°F | 61°F | 102°F 1971 | 37°F 1894 | 5% | 0% |
| Sep 14 | 75°F | 61°F | 104°F 1971 | 39°F 1894 | 5% | 0% |
| Sep 15 | 75°F | 61°F | 102°F 1971 | 36°F 1895 | 5% | 0% |
| Sep 16 | 75°F | 60°F | 103°F 1913 | 43°F 1896 | 5% | 0% |
| Sep 17 | 74°F | 60°F | 102°F 1913 | 40°F 1895 | 5% | 0% |
| Sep 18 | 74°F | 60°F | 100°F 1913 | 42°F 1907 | 6% | 0% |
| Sep 19 | 74°F | 60°F | 99°F 2000 | 39°F 1893 | 6% | 0% |
| Sep 20 | 74°F | 60°F | 100°F 1939 | 40°F 1895 | 6% | 0% |
| Sep 21 | 73°F | 59°F | 101°F 1928 | 39°F 1893 | 6% | 0% |
| Sep 22 | 73°F | 59°F | 101°F 1939 | 36°F 1895 | 6% | 0% |
| Sep 23 | 73°F | 59°F | 100°F 1939 | 35°F 1903 | 7% | 0% |
| Sep 24 | 73°F | 59°F | 98°F 1964 | 40°F 1895 | 7% | 0% |
| Sep 25 | 72°F | 58°F | 97°F 1952 | 42°F 1929 | 7% | 0% |
| Sep 26 | 72°F | 58°F | 98°F 1963 | 38°F 1893 | 7% | 0% |
| Sep 27 | 72°F | 58°F | 98°F 1921 | 41°F 1893 | 8% | 0% |
| Sep 28 | 71°F | 57°F | 98°F 1921 | 38°F 1894 | 8% | 0% |
| Sep 29 | 71°F | 57°F | 96°F 1997 | 42°F 1905 | 8% | 0% |
| Sep 30 | 71°F | 57°F | 95°F 2024 | 35°F 1893 | 8% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- September 1
- sunrise 6:38 AM, sunset 7:35 PM
- September 30
- sunrise 7:02 AM, sunset 6:51 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00045933 (Mt Hamilton), public domain. Records: NOAA GHCN-Daily, station USC00047821, 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.