Arroyo Grande, CA climate
Arroyo Grande has warm winters and cool summers, with very little rain. A typical July afternoon reaches 65°, a January night drops to 48°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Arroyo Grande feels like
Winter
Spring
Summer
Fall
Arroyo Grande 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 | 62° | 48° | 3.4" | 0.1" | 7 | 0 | 51° – 59° |
| February | 62° | 48° | 3.2" | 0 | 8 | 0 | 51° – 61° |
| March | 62° | 49° | 2.6" | 0 | 7 | 0 | 50° – 62° |
| April | 63° | 50° | 1.1" | 0 | 4 | 0 | 52° – 61° |
| May | 63° | 52° | 0.3" | 0 | 2 | 0 | 53° – 63° |
| June | 65° | 54° | 0.1" | 0 | 0 | 0 | 55° – 63° |
| July | 65° | 57° | 0.0" | 0 | 0 | 0 | 58° – 65° |
| August | 66° | 57° | 0.0" | 0 | 0 | 0 | 59° – 65° |
| September | 67° | 57° | 0.1" | 0 | 1 | 0 | 59° – 67° |
| October | 68° | 55° | 0.6" | 0 | 2 | 0 | 57° – 67° |
| November | 66° | 51° | 1.4" | 0 | 3 | 0 | 52° – 62° |
| December | 62° | 47° | 2.4" | 0 | 7 | 0 | 52° – 59° |
| Year | 64° | 52° | 15.2" | 0.1" | 42 | 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 Arroyo Grande
Arroyo Grande gets 15 inches of rain and melted snow a year. January is the wettest month and July the driest. Rain or snow falls on about 42 days a year.
A year-round growing season
Heating and cooling a home in Arroyo Grande
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Arroyo Grande, 91% of that work is heating and 9% 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.
Arroyo Grande and its neighbors
Arroyo Grande borders 3 towns with climate data. January nights across them vary by 1.1°. Pismo Beach has both the coldest January nights (46°) and the hottest July afternoons (68°). Arroyo Grande’s January low is 48° and its July high 65°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Arroyo Grande 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 Arroyo Grande averaged 2.0° warmer than the 1900s. The biggest change is in January (+2.7°). The shift is larger than in 93% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Arroyo Grande’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. March swings the most: between 1991 and 2020 its average temperature ranged from 50° to 62°. August is the most reliable, staying within 6°.
Common questions about Arroyo Grande’s climate
What is the coldest month in Arroyo Grande?
December, with a typical high of 62° and a low of 47°.
What is the hottest month in Arroyo Grande?
October, with a typical high of 68° and a low of 55°. About 1 days a year reach 90°.
How much snow does Arroyo Grande get?
Almost none. A normal year brings 0.1 inches.
When is the first frost in Arroyo Grande?
Frost is uncommon. Only 15% of years see a night at 32° or below.
What is the rainiest month in Arroyo Grande?
January, with 3.4 inches of rain and melted snow. The year totals 15 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Arroyo Grande itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Morro Bay Fire Dept, CA (22 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.