easeweather.com
Grass Valley (CA)
Akron (OH)Albuquerque (NM)Alexandria (VA)Anaheim (CA)Anchorage (AK)Arlington (VA)Asheville (NC)Atlanta (GA)Atlantic City (NJ)Austin (TX)Baltimore (MD)Baton Rouge (LA)Birmingham (AL)Boston (MA)Bowling Green (KY)Brooklyn (NY)Buffalo (NY)Cape Coral (FL)Charlotte (NC)Chattanooga (TN)Chicago (IL)Cincinnati (OH)Cleveland (OH)Colorado Springs (CO)Columbus (OH)Corpus Christi (TX)Dallas (TX)Dayton (OH)Daytona Beach (FL)Denver (CO)Des Moines (IA)Detroit (MI)El Paso (TX)Fairbanks (AK)Fort Lauderdale (FL)Fort Wayne (IN)Fort Worth (TX)Gatlinburg (TN)Grand Rapids (MI)
Grass Valley (CA)
Harrisburg (PA)Honolulu (HI)Houston (TX)Huntsville (AL)Indianapolis (IN)Jackson (MS)Jacksonville (FL)Juneau (AK)Kansas City (MO)Ketchikan (AK)Key West (FL)Knoxville (TN)Las Vegas (NV)Lexington (KY)Lincoln (NE)Little Rock (AR)Los Angeles (CA)Louisville (KY)Madison (WI)Manhattan (NY)Memphis (TN)Miami (FL)Milwaukee (WI)Minneapolis (MN)Mobile (AL)Montgomery (AL)Nashville (TN)New Orleans (LA)New York City (NY)Newark (NJ)Oklahoma City (OK)Omaha (NE)Orlando (FL)Philadelphia (PA)Phoenix (AZ)Pittsburgh (PA)Portland (OR)Richmond (VA)Sacramento (CA)Salt Lake City (UT)San Antonio (TX)San Diego (CA)San Francisco (CA)San Jose (CA)Savannah (GA)Seattle (WA)Sitka (AK)Skagway (AK)Springfield (MO)St. Louis (MO)St. Petersburg (FL)Tallahassee (FL)Tampa (FL)Toledo (OH)Traverse City (MI)Tulsa (OK)Tyler (TX)Vancouver (WA)Virginia Beach (VA)WashingtonWinston-Salem (NC) More Locations
United States weather

Weather in Grass Valley, California for September 2026

Your guide to Grass Valley weather in September - trends and predictions

    Temperatures

  • Until now, September 2026 in Grass Valley is cooler than usual, with temperatures averaging 26.1 °F, this is 2.2 °F below the typical seasonal average.

  • The forecast for the next days in Grass Valley predicts temperatures to be around 27 °F, close to the historical average.

  • In general, the average temperature in Grass Valley at the beginning of September is 28.6 °F. As the month progressed, temperatures tended to moderately fall, reaching an average of 27.6 °F by the end of September.

    • Rain 🌧️

  • Precipitation in Grass Valley during September is a rare event, with an average of fewer than 2 rainy days.

    • More

  • New! Chat with our AI weatherman - it’s amazing and free.

Average dry days
30
Dry days
Average rainy days
0
Rainy days
Average snowy days
0
Snow days
Average temperatures
29°/19°
Temperatures
Average wind speed
14 km/h
Avg max wind
Average humidity
43 %
Avg humidity

Grass Valley Weather September

Move between months or click on a day
August
October
Sun.Mon.Tue.Wed.Thu.Fri.Sat.
1
Sunny
31°
2
Sunny
28°
3
Sunny
27°
4
Sunny
29°
5
Sunny
28°
6
Sunny
28°
7
Sunny
29°
8
Sunny
31°
9
Thundery outbreaks possible
29°
10
Thundery outbreaks possible
27°
11
Cloudy
28°
12
Sunny
29°
13
Sunny
25°
14
Sunny
28°
15
Sunny
30°
16
Sunny
29°
17
Sunny
28°
18
Overcast
26°
19
Overcast
24°
20
Overcast
26°
21
Sunny
26°
22
Sunny
26°
23
Sunny
28°
24
Overcast
29°
25
Overcast
26°
26
Sunny
25°
27
Sunny
30°
28
Sunny
30°
29
Sunny
28°
30
Overcast
25°

Temperatures trend during September in Grass Valley

See the weather trend as well as the moving average line

September weather in Grass Valley day by day

Click on a date for more information
August October
Date Weather Temperatures Rain UV More
Sept. 1 Sunny
Sunny
 31° /17° 0 mm 8
Sept. 2 Sunny
Sunny
 28° /17° 0.1 mm 7
Sept. 3 Sunny
Sunny
 27° /16° 0.2 mm 7
Sept. 4 Sunny
Sunny
 29° /18° 12.3 mm 6
Sept. 5 Sunny
Sunny
 28° /15° 0 mm 9
Sept. 6 Sunny
Sunny
 28° /16° 0 mm 8
Sept. 7 Sunny
Sunny
 29° /15° 0 mm 8
Sept. 8 Sunny
Sunny
 31° /16° 0 mm 8
Sept. 9 Thundery outbreaks possible
Thundery outbreaks possible
 29° /17° 0 mm 4
Sept. 10 Thundery outbreaks possible
Thundery outbreaks possible
 27° /17° 0 mm 7
Sept. 11 Cloudy
Cloudy
 28° /16° 0 mm 7
Sept. 12 Sunny
Sunny
 29° /16° 0 mm 8
Sept. 13 Sunny
Sunny
 25° /15° 0 mm 8
Sept. 14 Sunny
Sunny
 28° /15° 0 mm 8
Sept. 15 Sunny
Sunny
 30° /16° 0 mm 8
Sept. 16 Sunny
Sunny
 29° /17° 0 mm 8
Sept. 17 Sunny
Sunny
 28° /15° 0 mm 8
Sept. 18 Overcast
Overcast
 26° /16° 0 mm 7
Sept. 19 Overcast
Overcast
 24° /15° 0 mm 6
Sept. 20 Overcast
Overcast
 26° /19° 0 mm 5.6
Sept. 21 Sunny
Sunny
 26° /19° 0 mm 5.9
Sept. 22 Sunny
Sunny
 26° /18° 0 mm 6.4
Sept. 23 Sunny
Sunny
 28° /20° 0 mm 5.6
Sept. 24 Overcast
Overcast
 29° /20° 0 mm 6
Sept. 25 Overcast
Overcast
 26° /19° 0 mm 7
Sept. 26 Sunny
Sunny
 25° /18° 0 mm 7
Sept. 27 Sunny
Sunny
 30° /19° 0 mm 7
Sept. 28 Sunny
Sunny
 30° /20° 0 mm 8
Sept. 29 Sunny
Sunny
 28° /20° 0 mm 7
Sept. 30 Overcast
Overcast
 25° /19° 0 mm 5
Next
Important Notice
Our weather forecast for Grass Valley in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Grass Valley forecast closer to your planned date for the most up-to-date weather information.
Change Month
‹
›

Grass Valley in September - FAQ

What are the expected maximum and minimum temperatures in Grass Valley during September?
During September, expect a variety of temperatures with highs around 29° and lows near 19°, suitable for diverse activities and preferences.

How much rainfall should be expected in Grass Valley during September?
Rainfall in Grass Valley during September is rare to nonexistent, with the total expected rainfall being less than 10 mm and approximately 0 days seeing any precipitation. Planning without the concern for rain is generally straightforward during this very dry period.

What are the typical wind conditions in Grass Valley during September?
The average wind speed in Grass Valley during September is 14 km/h, suggesting breezy to windy conditions, depending on your activities.

September rainfall patterns in Grass Valley

Explore the daily rainfall trends and prepare for Grass Valleys September weather 💧

UV exposure in Grass Valley during September

Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️

Quick links

More Grass Valley weather pages
You are here
Location coordinates Where is Grass Valley?

Get accurate weather forecasts for Grass Valley, located at latitude 39.219 and longitude -121.061. Stay updated with localized weather information tailored for Grass Valley.

Found a mistake?
We appreciate your attention to details. Tell us here.