Silicon Valley in september: average Weather, Temperature and Climate
Weather in Silicon Valley in september 2025
The weather in Silicon Valley in september comes from statistical datas on the last years. You can view the weather statistics for the whole month, but also by clicking on the tabs for the beginning, the middle and the end of the month.
Average weather throughout september
perfect weather UV index: 7
Weather at 6am
65°F
Clear/Sunny
82% of time
13%
4%
3%
Weather at 12pm
83°F
Clear/Sunny
89% of time
6%
4%
3%
Weather at 6pm
70°F
Clear/Sunny
90% of time
6%
3%
2%
Weather at 3am
61°F
82%
9%
7%
3%
Evolution of daily average temperature and precipitation in Silicon Valley in september
These charts show the evolution of average minimum/maximum temperatures as well as average daily precipitation volume in Silicon Valley in september.
The climate of Silicon Valley in september is perfect
The climate in september in Silicon Valley is dry ; it never rains.
The climate good around this city september. The high seasonal norm is 83°F. In the morning the temperature drops to 65°F. Thus, the mean temperature average in september in Silicon Valley is 74°F. These temperatures are far removed from those records observed in Silicon Valley in the month of september with a maximum record of 112°F in 2017 and a minimum record of 49°F in 2021. You You can hope to have about 10 days with temperatures up to 86°F, or 33 of the month.
On average, in Silicon Valley, the days of september last 12:24. Sunrise is at 05:51 and sunset is at 18:15.
With ideal weather conditions, this month is recommended to go in this locality in California.
Seasonal average climate and temperature of Silicon Valley in september
Check below seasonal norms These datas are compiled from the weather statements earlier years of the month of september.
| September | |||||
| Outside temperature | |||||
| Average temperature | 74°F | ||||
| Highest temperature | 83°F | ||||
| Lowest temperature | 65°F | ||||
| Highest record temperature | 112°F (2017) | ||||
| Lowest record temperature | 49°F (2021) | ||||
| Number of days at +86°F | 10 day(s) (33%) | ||||
| Number of days at +65°F | 30 day(s) (100%) | ||||
| Wind | |||||
| Wind speed | 15km/h | ||||
| Wind temperature | 67°F | ||||
| Precipitation (rainfall) | |||||
| Rainfall | 0.2in | ||||
| Number of days with rainfall | 0 day(s) (1%) | ||||
| Record daily rainfall | 0.4in (2017) | ||||
| Other climate data | |||||
| Humidity | 71% | ||||
| Visibility | 9.74km | ||||
| Cloud cover | 9% | ||||
| UV index | 7 | ||||
| Daily sunshine hours | 13 | ||||
| Sunrise and sunset | |||||
| Time of sunrise | 05:51 | ||||
| Time of sunset | 18:15 | ||||
| Length of day | 12:24 | ||||
| Our opinion about the weather in september | |||||
| Our opinion at whereandwhen.net | perfect | ||||
How was the weather last september?
Here is the day by day recorded weather in Silicon Valley in september 2024:
54°F to 79°F
52°F to 81°F
58°F to 95°F
63°F to 97°F
63°F to 97°F
63°F to 94°F
58°F to 88°F
56°F to 88°F
59°F to 88°F
52°F to 83°F
52°F to 77°F
52°F to 81°F
54°F to 86°F
56°F to 85°F
52°F to 70°F
54°F to 68°F
56°F to 59°F
59°F to 65°F
56°F to 76°F
56°F to 76°F
52°F to 83°F
59°F to 90°F
63°F to 97°F
67°F to 95°F
59°F to 81°F
54°F to 83°F
56°F to 92°F
59°F to 85°F
54°F to 86°F
56°F to 95°F
Map: other cities in California in september
Cities near Silicon Valley:
| San Jose in september | perfect weather |
| Pescadero in september | perfect weather |
| Half Moon Bay in september | perfect weather |
| Moss Beach in september | perfect weather |
| Santa Cruz California in september | perfect weather |
| Oakland in september | perfect weather |
| San Francisco in september | perfect weather |
| Golden Gate National Recreation Area in september | perfect weather |
| Stinson Beach in september | perfect weather |
| Pacific Grove in september | perfect weather |
| Stockton in september | perfect weather |
| Carmel-by-the-Sea in september | perfect weather |
Click over cities on the map for information about the weather in september.
Silicon Valley
perfect weather
good
tolerable
bad
very bad
Weather data for Silicon Valley in september:
Weather data for Silicon Valley for september are derived from an average of the weather forecast since 2009 in Silicon Valley. There is a margin of error and these forecasts are to be considered as general information only. The weather in Silicon Valley can vary slightly from year to year, but this data should limit surprises. So you can pack your bags or check for the best time in year to go to Silicon Valley.