Napa Valley in september: average Weather, Temperature and Climate
Weather in Napa Valley in september 2025
The weather in Napa Valley in the month of september comes from statistical datas on the last years. You can view the weather statistics the entire month, but also navigating through 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
61°F
Clear/Sunny
84% of time
12%
3%
2%
Weather at 12pm
88°F
Clear/Sunny
89% of time
8%
4%
1%
Weather at 6pm
72°F
Clear/Sunny
90% of time
10%
2%
1%
Weather at 3am
58°F
83%
8%
8%
2%
Evolution of daily average temperature and precipitation in Napa Valley in september
These charts show the evolution of average minimum/maximum temperatures as well as average daily precipitation volume in Napa Valley in september.
The climate of Napa Valley in september is perfect
The climate in september in Napa Valley is dry ; it never rains.
The climate nice in this location the month of september. The high seasonal norm is 88°F. The seasonal minimum is 61°F. Thus, the mean temperature average on this month of september in Napa Valley is 76°F. Note that seasonal normals in contrast with those observed in Napa Valley in the month of september with a maximum record of 117°F in 2017 and a minimum record of 45°F in 2021. You can expect to have about 17 days with temperatures up to 86°F, or 57 of time.
Day length in Napa Valley in september is 12:25. Sunrise is at 05:52 and sunset is at 18:17.
With a perfect weather, this month is recommended to go in that area.
Seasonal average climate and temperature of Napa Valley in september
Check below seasonal norms These datas are compiled from the weather statements earlier years of september.
| September | |||||
| Outside temperature | |||||
| Average temperature | 76°F | ||||
| Highest temperature | 88°F | ||||
| Lowest temperature | 61°F | ||||
| Highest record temperature | 117°F (2017) | ||||
| Lowest record temperature | 45°F (2021) | ||||
| Number of days at +86°F | 17 day(s) (57%) | ||||
| Number of days at +65°F | 30 day(s) (100%) | ||||
| Wind | |||||
| Wind speed | 13km/h | ||||
| Wind temperature | 61°F | ||||
| Precipitation (rainfall) | |||||
| Rainfall | 0.2in | ||||
| Number of days with rainfall | 0 day(s) (0%) | ||||
| Record daily rainfall | 0.2in (2013) | ||||
| Other climate data | |||||
| Humidity | 65% | ||||
| Visibility | 9.76km | ||||
| Cloud cover | 8% | ||||
| UV index | 7 | ||||
| Daily sunshine hours | 13 | ||||
| Sunrise and sunset | |||||
| Time of sunrise | 05:52 | ||||
| Time of sunset | 18:17 | ||||
| Length of day | 12:25 | ||||
| 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 Napa Valley in september 2024:
50°F to 83°F
47°F to 86°F
61°F to 101°F
65°F to 101°F
63°F to 103°F
65°F to 97°F
52°F to 90°F
54°F to 90°F
58°F to 90°F
52°F to 83°F
52°F to 85°F
50°F to 86°F
52°F to 90°F
54°F to 85°F
54°F to 74°F
49°F to 70°F
54°F to 67°F
59°F to 74°F
58°F to 83°F
52°F to 83°F
54°F to 86°F
63°F to 95°F
70°F to 99°F
72°F to 101°F
54°F to 81°F
54°F to 90°F
67°F to 97°F
59°F to 90°F
56°F to 95°F
67°F to 101°F
Map: other cities in California in september
Cities near Napa Valley:
| Bodega Bay in september | perfect weather |
| Stinson Beach in september | perfect weather |
| Jenner in september | perfect weather |
| Golden Gate National Recreation Area in september | perfect weather |
| Point Reyes in september | perfect weather |
| Oakland in september | perfect weather |
| San Francisco in september | perfect weather |
| Timber Cove in september | perfect weather |
| Sacramento in september | perfect weather |
| Sea Ranch in september | perfect weather |
| Moss Beach in september | perfect weather |
| Gualala in september | perfect weather |
Click over cities on the map for information about the weather in september.
Napa Valley
perfect weather
good
tolerable
bad
very bad
Weather data for Napa Valley in september:
Weather data for Napa Valley for september are derived from an average of the weather forecast since 2009 in Napa Valley. There is a margin of error and these forecasts are to be considered as general information only. The weather in Napa 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 Napa Valley.