30-year climate normals

Mendocino County Climate and Weather Averages

Hottest month — July

83.5°

average daily high. The coldest month is December, averaging a low of 32.3°F.

Mendocino County gets 49.23" of precipitation a year, and 56% of it falls in Dec, Jan, Feb.

Temperature through the year

Each bar spans the average daily low to the average daily high for that month.

Month	Avg high	Avg low	Precip
January	53.7°	33.3°	9.17"
February	56.3°	34.1°	8.63"
March	59.0°	35.5°	7.07"
April	61.8°	37.3°	3.44"
May	68.9°	40.2°	1.78"
June	75.5°	44.2°	0.50"
July	83.5°	48.0°	0.04"
August	83.3°	45.6°	0.05"
September	81.9°	42.1°	0.37"
October	72.4°	36.9°	2.57"
November	59.9°	35.3°	5.77"
December	53.0°	32.3°	9.84"

Rainfall by month

Mendocino County has a distinct wet season. 56% of the year's precipitation arrives in Dec, Jan, Feb.

January 9.17"

February 8.63"

March 7.07"

April 3.44"

May 1.78"

June 0.50"

July 0.04"

August 0.05"

September 0.37"

October 2.57"

November 5.77"

December 9.84"

Annual total 49.23"

What this climate costs you

Degree days measure how hard a building has to work to stay comfortable. They are the reason two identical houses have very different power bills, and they are the link between the weather here and what you pay every month.

Cooling degree days How much air conditioning the climate demands 195

Heating degree days How much heating the climate demands 4,527

Approximate annual cooling cost At 33.25¢/kWh, California average $65

Approximate annual electric heating cost Lower where heating is gas rather than electric $527

These are rough planning figures from degree days and the state electricity price, not a bill estimate. House size, insulation and fuel type move them a lot. See the full cost of owning a home in Mendocino County, where electricity is one line of eight.

Common questions

What is the weather like in Mendocino County?

Mendocino County averages a high of 83.5°F in July and a low of 32.3°F in December. Annual precipitation is 49.23 inches, with essentially no snow.

When is the rainy season in Mendocino County?

The wettest stretch is Dec, Jan, Feb, which accounts for 56% of the year's precipitation. That is a pronounced wet season rather than rain spread evenly through the year.

How hot does it get in Mendocino County?

The average daily high in July, the hottest month, is 83.5°F. That drives 195 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Mendocino County?

Effectively no. Measurable snowfall is rare in Mendocino County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station WILLITS 1 NE, CA US (USC00049684), 5.4 miles from the county centroid.
Heating and cooling degree days — NOAA, same station and period.
Electricity price — US Energy Information Administration, Electric Power Monthly Table 5.6.A, California residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.