Rio Dell, CA climate
Rio Dell has warm winters and cool summers, with plenty of rain. A typical July afternoon reaches 74°, a January night drops to 41°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Rio Dell feels like
Winter
Spring
Summer
Fall
Rio Dell weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 54° | 41° | 8.7" | 0.1" | 16 | 0 | 44° – 54° |
| February | 56° | 41° | 7.8" | 0.1" | 14 | 0 | 43° – 53° |
| March | 58° | 42° | 7.3" | 0.3" | 15 | 0 | 46° – 54° |
| April | 61° | 44° | 4.1" | 0 | 13 | 0 | 50° – 57° |
| May | 66° | 48° | 2.0" | 0 | 9 | 0 | 53° – 61° |
| June | 69° | 51° | 0.6" | 0 | 5 | 0 | 56° – 63° |
| July | 74° | 54° | 0.1" | 0 | 2 | 0 | 62° – 67° |
| August | 76° | 54° | 0.1" | 0 | 2 | 0 | 63° – 67° |
| September | 75° | 52° | 0.5" | 0 | 2 | 0 | 60° – 68° |
| October | 68° | 47° | 2.5" | 0 | 6 | 0 | 55° – 62° |
| November | 58° | 43° | 5.5" | 0 | 13 | 0 | 44° – 54° |
| December | 53° | 40° | 9.9" | 0.2" | 15 | 0 | 43° – 50° |
| Year | 64° | 46° | 49.2" | 0.7" | 112 | 0 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Rio Dell
Rio Dell gets 49 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 112 days a year.
A year-round growing season
Heating and cooling a home in Rio Dell
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Rio Dell, 98% of that work is heating and 2% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Rio Dell compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Rio Dell averaged 1.5° warmer than the 1900s. The biggest change is in January (+2.4°). The shift is larger than in 68% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Rio Dell’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. November swings the most: between 1991 and 2020 its average temperature ranged from 44° to 54°. August is the most reliable, staying within 5°.
Common questions about Rio Dell’s climate
What is the coldest month in Rio Dell?
December, with a typical high of 53° and a low of 40°.
What is the hottest month in Rio Dell?
August, with a typical high of 76° and a low of 54°. About 2 days a year reach 90°.
How much snow does Rio Dell get?
Almost none. A normal year brings 0.7 inches.
When is the first frost in Rio Dell?
Frost is uncommon. Only 84% of years see a night at 32° or below.
What is the rainiest month in Rio Dell?
December, with 9.9 inches of rain and melted snow. The year totals 49 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Rio Dell itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Grizzly Creek Sp, CA (11 mi, snow) and Scotia, CA (1 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.