San Jose weather in September: San Jose, California: normal highs, lows, rain and records for September
San Jose in September has a normal high of 81°F and a normal low of 57°F, a daily mean of 69°F, falling from 82°F on the 1st to 79°F by the 30th. Measurable precipitation falls on 1 days in a normal September, 0.07 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 27°C and low of 14°C, 2 mm of precipitation in September.
- NOAA stationSan Jose
- Station IDUSW00023293
- Location37.36°N 121.92°W
- Elevation51 ft (16 m)
- From the center7 miles
- Population997,368
- Jan 60° 42°
- Feb 62° 44°
- Mar 66° 46°
- Apr 69° 48°
- May 74° 52°
- Jun 79° 56°
- Jul 81° 58°
- Aug 81° 59°
- Sep 81° 57°
- Oct 76° 53°
- Nov 66° 46°
- Dec 60° 42°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is San Jose in September?
The normal high is 81°F and the normal low 57°F, for a daily mean of 69.0°F. September is 1.0°F cooler than August and 4.7°F warmer than October. September is the 3rd warmest month of the year in San Jose and the 10th wettest. Across the month the normal high falls 3°F, from 82°F on September 1 to 79°F on September 30. From one year to the next September's mean temperature typically moves about 1.7°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 67°F and 71°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 5%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 82°F | 58°F | 2% | 0% |
| September 8 | 82°F | 58°F | 2% | 1% |
| September 15 | 81°F | 57°F | 3% | 1% |
| September 22 | 80°F | 57°F | 4% | 2% |
| September 30 | 79°F | 56°F | 5% | 2% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 82°F | 58°F | 2% | 0% | 13 h |
| September 2 | 82°F | 58°F | 2% | 0% | 13 h |
| September 3 | 82°F | 58°F | 2% | 0% | 13 h |
| September 4 | 82°F | 58°F | 2% | 0% | 12 h 50 min |
| September 5 | 82°F | 58°F | 2% | 0% | 12 h 50 min |
| September 6 | 82°F | 58°F | 2% | 0% | 12 h 50 min |
| September 7 | 82°F | 58°F | 2% | 1% | 12 h 50 min |
| September 8 | 82°F | 58°F | 2% | 1% | 12 h 50 min |
| September 9 | 82°F | 58°F | 2% | 1% | 12 h 40 min |
| September 10 | 81°F | 58°F | 3% | 1% | 12 h 40 min |
| September 11 | 81°F | 58°F | 3% | 1% | 12 h 40 min |
| September 12 | 81°F | 58°F | 3% | 1% | 12 h 40 min |
| September 13 | 81°F | 58°F | 3% | 1% | 12 h 30 min |
| September 14 | 81°F | 58°F | 3% | 1% | 12 h 30 min |
| September 15 | 81°F | 57°F | 3% | 1% | 12 h 30 min |
| September 16 | 81°F | 57°F | 3% | 1% | 12 h 30 min |
| September 17 | 81°F | 57°F | 3% | 1% | 12 h 20 min |
| September 18 | 81°F | 57°F | 3% | 1% | 12 h 20 min |
| September 19 | 81°F | 57°F | 3% | 1% | 12 h 20 min |
| September 20 | 80°F | 57°F | 4% | 1% | 12 h 20 min |
| September 21 | 80°F | 57°F | 4% | 1% | 12 h 10 min |
| September 22 | 80°F | 57°F | 4% | 2% | 12 h 10 min |
| September 23 | 80°F | 57°F | 4% | 2% | 12 h 10 min |
| September 24 | 80°F | 57°F | 4% | 2% | 12 h 10 min |
| September 25 | 80°F | 56°F | 4% | 2% | 12 h 10 min |
| September 26 | 80°F | 56°F | 4% | 2% | 12 h |
| September 27 | 79°F | 56°F | 5% | 2% | 12 h |
| September 28 | 79°F | 56°F | 5% | 2% | 12 h |
| September 29 | 79°F | 56°F | 5% | 2% | 12 h |
| September 30 | 79°F | 56°F | 5% | 2% | 11 h 50 min |
- Normal high
- 81°FSeptember average
- Normal low
- 57°FSeptember average
- Precipitation
- 0.07 inmonth total
- Days with precipitation
- 10.01 inch or more
- Days at 90°F or more
- 5
- Daylight
- 13 h to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 29
- Days at 80°F or more
- 14
- Sunshine
- 95%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00023293; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in San Jose in September?
On a given September day the chance of 0.01 inch or more is 3% on average, highest around September 30 (5%). In all, 0.07 in falls on 1 days of a normal September.
In a normal September in San Jose, 5 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00023293.
What are the records for September in San Jose?
The warmest September temperature on San Jose's official record (since 1893) is 109°F, on September 6, 2022; the coldest is 35°F, on September 30, 1893. The wettest September brought 6.33 in (1918).
The September mean against the 1991-2020 normal of 69.0°F: 2021 70.1°F (+1.1), 2022 72.8°F (+3.8), 2023 69.5°F (+0.5), 2024 71.8°F (+2.8), 2025 71.8°F (+2.8), 2026 69.1°F (+0.1). 6 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 70.1°F | +1.1°F | 0.00 in |
| 2022 | 72.8°F | +3.8°F | 0.51 in |
| 2023 | 69.5°F | +0.5°F | 0.08 in |
| 2024 | 71.8°F | +2.8°F | 0.00 in |
| 2025 | 71.8°F | +2.8°F | 0.44 in |
| 2026 | 69.1°F | +0.1°F | 0.06 in |
Source: records: ACIS, NWS threaded record SJCthr; recent months: ACIS, station USW00023293. Records and recent months use complete months only.
How does September in San Jose compare across California?
Across the 219 places PlainClimate covers in California, September normal highs run from 64°F in Eureka to 104°F in Brawley; San Jose's is 81°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.