30-year climate normals
Glenn County Climate and Weather Averages
Hottest month — July
95.9°average daily high. The coldest month is December, averaging a low of 33.0°F.
Glenn County gets 21.36" of precipitation a year, and 59% 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 | 56.1° | 33.8° | 4.50" |
| February | 59.6° | 35.5° | 4.02" |
| March | 64.2° | 38.0° | 2.75" |
| April | 70.2° | 41.1° | 1.35" |
| May | 79.5° | 47.8° | 1.07" |
| June | 89.0° | 55.1° | 0.54" |
| July | 95.9° | 60.9° | 0.05" |
| August | 94.6° | 58.8° | 0.05" |
| September | 90.1° | 53.6° | 0.12" |
| October | 78.6° | 45.6° | 0.93" |
| November | 64.2° | 37.4° | 2.00" |
| December | 55.6° | 33.0° | 3.98" |
Rainfall by month
Glenn County has a distinct wet season. 59% of the year's precipitation arrives in Dec, Jan, Feb.
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.
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 Glenn County, where electricity is one line of eight.
Common questions
What is the weather like in Glenn County?
Glenn County averages a high of 95.9°F in July and a low of 33.0°F in December. Annual precipitation is 21.36 inches, with essentially no snow.
When is the rainy season in Glenn County?
The wettest stretch is Dec, Jan, Feb, which accounts for 59% 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 Glenn County?
The average daily high in July, the hottest month, is 95.9°F. That drives 1,364 cooling degree days a year, which is what your air conditioning has to work against.
Does it snow in Glenn County?
Effectively no. Measurable snowfall is rare in Glenn County.
Sources
- Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station STONY GORGE RSVR, CA US (USC00048587), 7.1 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.