San Jose, California weather in September
Temperature, rain and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Excellent
Best time to visit: April – October
What is the weather like in San Jose, California in September?
In September, San Jose, California is warm: daytime highs average 27 °C, and nights cool down to about 15 °C. With around 9 hours of sunshine a day, there is plenty of sun. It hardly ever rains. On about 7 days the thermometer climbs to 30 °C or more. All in all, September is an excellent month for a holiday in San Jose, California.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 98 | 100 | 96 |
| Day | 27° | 27° | 23° |
| Night | 15° | 15° | 13° |
| Sun | 10 h | 9 h | 8 h |
| Rain days | 0 | 1 | 3 |
More details for September
- Daylight
- 12 h 29 min06:49 – 19:17
- UV index
- 7 · highclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 18 km/haverage daily peakAll months
- Cloud cover
- 24 %on averageAll months
- Hot days
- 7 days30 °C or moreAll months
- Time zone
- UTC−7America/Los_Angeles
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %100 %
- Few rainy daysweight 30 %100 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- A jumper for the evenings
San Jose, California in September: quick answers
Is San Jose, California hot in September?
Warm rather than hot: in September, daytime highs in San Jose, California average 27 °C and nights cool to about 15 °C. On about 7 days the thermometer climbs to 30 °C or more.
Does it rain much in San Jose, California in September?
It hardly ever rains.
San Jose, California month by month
The whole year in San Jose, CaliforniaAll destinations: USAWhere to go in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences