San Jose Weather in September
Average highs run from 82°F on September 1 to 74°F on September 30, and lows from 59°F to 49°F. Normal precipitation for the month is 3.55 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
- 54°F
- Precipitation
- 3.55 in
- Record high
- 104°FSep 6, 1954
- Record low
- 22°FSep 26, 1928
- Chance of a freeze
- 7%
- Days of 90°F or more
- 3.4
- Daylight
- 13 h 04 min to 11 h 48 min
- Cloud cover
- 47%
- Humidity
- 70%
- Dew point
- 55°F
- Wind
- 8.7 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 | 82°F | 59°F | 102°F 1953 | 39°F 1915 | 23% | 0% |
| Sep 2 | 82°F | 59°F | 101°F 1953 | 41°F 2017 | 23% | 0% |
| Sep 3 | 82°F | 58°F | 100°F 1913 | 41°F 1952 | 23% | 0% |
| Sep 4 | 82°F | 58°F | 102°F 1954 | 36°F 1928 | 23% | 0% |
| Sep 5 | 82°F | 58°F | 103°F 1954 | 41°F 1918 | 23% | 0% |
| Sep 6 | 82°F | 57°F | 104°F 1954 | 39°F 1928 | 23% | 0% |
| Sep 7 | 81°F | 57°F | 100°F 1939 | 38°F 1956 | 23% | 0% |
| Sep 8 | 81°F | 57°F | 98°F 1922 | 36°F 1986 | 23% | 0% |
| Sep 9 | 81°F | 56°F | 98°F 1955 | 40°F 2024 | 23% | 0% |
| Sep 10 | 81°F | 56°F | 97°F 1912 | 36°F 1924 | 23% | 0% |
| Sep 11 | 80°F | 56°F | 96°F 1931 | 32°F 1917 | 23% | 0% |
| Sep 12 | 80°F | 55°F | 97°F 1939 | 36°F 1917 | 24% | 0% |
| Sep 13 | 80°F | 55°F | 100°F 1939 | 35°F 1953 | 24% | 0% |
| Sep 14 | 80°F | 55°F | 100°F 1939 | 31°F 1923 | 24% | 0% |
| Sep 15 | 79°F | 54°F | 100°F 1939 | 37°F 2007 | 24% | 0% |
| Sep 16 | 79°F | 54°F | 98°F 1939 | 31°F 1916 | 24% | 0% |
| Sep 17 | 79°F | 53°F | 98°F 1954 | 34°F 1918 | 24% | 0% |
| Sep 18 | 78°F | 53°F | 97°F 1906 | 29°F 1916 | 24% | 0% |
| Sep 19 | 78°F | 53°F | 97°F 1925 | 33°F 1916 | 24% | 0% |
| Sep 20 | 78°F | 52°F | 94°F 1940 | 31°F 1918 | 24% | 0% |
| Sep 21 | 77°F | 52°F | 94°F 1940 | 34°F 1918 | 24% | 0% |
| Sep 22 | 77°F | 52°F | 94°F 1956 | 28°F 1995 | 24% | 0% |
| Sep 23 | 77°F | 51°F | 93°F 2017 | 29°F 1995 | 25% | 0% |
| Sep 24 | 76°F | 51°F | 93°F 1935 | 28°F 1928 | 25% | 0% |
| Sep 25 | 76°F | 51°F | 92°F 1920 | 32°F 1928 | 25% | 0% |
| Sep 26 | 75°F | 50°F | 91°F 1920 | 22°F 1928 | 25% | 0% |
| Sep 27 | 75°F | 50°F | 92°F 1954 | 29°F 1918 | 25% | 0% |
| Sep 28 | 74°F | 50°F | 96°F 1953 | 26°F 1942 | 25% | 0% |
| Sep 29 | 74°F | 49°F | 101°F 1953 | 33°F 1949 | 25% | 0% |
| Sep 30 | 74°F | 49°F | 93°F 1952 | 27°F 1912 | 25% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 6:26 AM, sunset 7:30 PM
- September 30
- sunrise 6:54 AM, sunset 6:42 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00115413 (Mason City 4SE), public domain. Records: NOAA GHCN-Daily, station USC00115079, 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.