Gilroy, CA climate
Gilroy has mild winters and pleasant summers, with very little rain. A typical July afternoon reaches 82°, a January night drops to 39°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Gilroy feels like
Winter
Spring
Summer
Fall
Gilroy 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 | 61° | 39° | 4.5" | 0 | 10 | 0 | 46° – 54° |
| February | 64° | 41° | 4.1" | 0 | 10 | 0 | 49° – 58° |
| March | 67° | 43° | 3.4" | 0 | 8 | 0 | 50° – 61° |
| April | 71° | 45° | 1.4" | 0 | 5 | 0 | 54° – 62° |
| May | 75° | 49° | 0.6" | 0 | 3 | 0 | 58° – 67° |
| June | 80° | 53° | 0.1" | 0 | 1 | 0 | 63° – 69° |
| July | 82° | 55° | 0.0" | 0 | 0 | 0 | 66° – 72° |
| August | 83° | 55° | 0.1" | 0 | 0 | 0 | 66° – 72° |
| September | 82° | 53° | 0.1" | 0 | 1 | 0 | 65° – 72° |
| October | 78° | 49° | 0.9" | 0 | 3 | 0 | 60° – 68° |
| November | 68° | 42° | 1.9" | 0 | 6 | 0 | 48° – 59° |
| December | 60° | 38° | 4.0" | 0 | 9 | 0 | 45° – 53° |
| Year | 72° | 47° | 20.9" | 0.0" | 55 | 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 Gilroy
Gilroy gets 21 inches of rain and melted snow a year. January is the wettest month and July the driest. Rain or snow falls on about 55 days a year.
About 277 frost-free days a year
In half of years the last 32° night comes by February 24 and the first one by November 27. That leaves about 277 frost-free days for gardens, longer than 93% of U.S. towns.
Heating and cooling a home in Gilroy
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Gilroy, 78% of that work is heating and 22% is cooling.
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 Gilroy 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 Gilroy averaged 1.9° warmer than the 1900s. The biggest change is in January (+2.9°). The shift is larger than in 91% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Gilroy’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 48° to 59°. August is the most reliable, staying within 6°.
Common questions about Gilroy’s climate
What is the coldest month in Gilroy?
December, with a typical high of 60° and a low of 38°.
What is the hottest month in Gilroy?
August, with a typical high of 83° and a low of 55°. About 48 days a year reach 90°.
How much snow does Gilroy get?
Almost none. A normal year brings 0.0 inches.
When is the first frost in Gilroy?
In half of years the first 32° night comes by November 27, and the last spring frost by February 24.
What is the rainiest month in Gilroy?
January, with 4.5 inches of rain and melted snow. The year totals 21 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Gilroy itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Gilroy, CA (1 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.