Grass Valley
California, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Grass Valley, CA

The first month of the autumn, September, is still a warm month in Grass Valley, California, with average temperature varying between 50.5°F (10.3°C) and 82.2°F (27.9°C).

Temperature

In Grass Valley, the average high-temperature in September is practically the same as in August - a warm 82.2°F (27.9°C). The average low-temperature, in Grass Valley, is 50.5°F (10.3°C).

Rainfall

In Grass Valley, it is raining for 2.2 days, with typically 0.8" (20.1mm) of accumulated precipitation. Throughout the year, in Grass Valley, there are 84.6 rainfall days, and 53.2" (1352.4mm) of precipitation is accumulated.

Snowfall

In Grass Valley snow does not fall in May through October.

Daylight

The average length of the day in September in Grass Valley is 12.4h.

What is the temperature in September in Grass Valley?

In Grass Valley, in September, the average high-temperature is 82.2°F (27.9°C), and the average low-temperature is 50.5°F (10.3°C).

How much does it rain in Grass Valley in September?

In Grass Valley, in September, during 2.2 rainfall days, 0.8" (20.1mm) of precipitation is typically accumulated.

When it does not snow in Grass Valley?

May through October are months without snowfall.

What is the average length of the day in September in Grass Valley?

In September, the average length of the day in Grass Valley is 12.4h.
Average temperature in September - Grass Valley, CA
  • Average high temperature in September: 82.2°F

The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is December (53.1°F).

  • Average low temperature in September: 50.5°F

The month with the highest average low temperature is July (56.2°F).
The coldest month (with the lowest average low temperature) is December (31.7°F).

Average rainfall in September - Grass Valley, CA
  • Average rainfall in September: 0.8"

The wettest month (with the highest rainfall) is January (9.7").
The driest month (with the lowest rainfall) is July (0.1").

Average rainfall days in September - Grass Valley, CA
  • Average rainfall days in September: 2.2 days

The month with the highest number of rainy days is January (13.1 days).
The month with the lowest number of rainy days is July (0.2 days).

Average snowfall in September - Grass Valley, CA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.5").
Months with the lowest snowfall are May, June, July, August, September and October (0").

Average snowfall days in September - Grass Valley, CA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is March (1.1 days).
Months with the lowest number of snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September - Grass Valley, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.9h).
The month with shortest days is December (Average daylight: 9.5h).