Palo Alto, CA climate
Palo Alto has warm winters and pleasant summers, with very little rain. A typical July afternoon reaches 80°, a January night drops to 40°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decade11° warmer than normal today. The forecast high is 88°, and a typical Sep 30 in Palo Alto peaks around 77°.Live forecast: National Weather Service · Normal: NOAA 1991–2020
What a year in Palo Alto feels like
Winter
Spring
Summer
Fall
Palo Alto 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 | 60° | 40° | 4.1" | 0 | 10 | 0 | 47° – 54° |
| February | 62° | 42° | 4.1" | 0 | 10 | 0 | 48° – 57° |
| March | 66° | 44° | 3.2" | 0 | 8 | 0 | 50° – 60° |
| April | 68° | 45° | 1.5" | 0 | 5 | 0 | 53° – 60° |
| May | 72° | 49° | 0.6" | 0 | 3 | 0 | 57° – 65° |
| June | 78° | 52° | 0.2" | 0 | 1 | 0 | 61° – 68° |
| July | 80° | 55° | 0.0" | 0 | 0 | 0 | 65° – 71° |
| August | 80° | 55° | 0.0" | 0 | 0 | 0 | 65° – 71° |
| September | 80° | 53° | 0.1" | 0 | 1 | 0 | 63° – 70° |
| October | 75° | 49° | 0.9" | 0 | 3 | 0 | 59° – 68° |
| November | 66° | 44° | 2.1" | 0 | 6 | 0 | 49° – 58° |
| December | 59° | 40° | 4.1" | 0 | 10 | 0 | 46° – 55° |
| Year | 70° | 47° | 20.9" | 0.0" | 56 | 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 Palo Alto
Palo Alto 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 56 days a year.
About 310 frost-free days a year
In half of years the last 32° night comes by February 1 and the first one by December 7. That leaves about 310 frost-free days for gardens, longer than 95% of U.S. towns.
Heating and cooling a home in Palo Alto
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Palo Alto, 88% of that work is heating and 12% 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.
Palo Alto and its neighbors
Palo Alto borders 7 towns with climate data. January nights across them vary by 3.6°. Los Altos has both the coldest January nights (40°) and the hottest July afternoons (82°). Palo Alto’s January low is 40° and its July high 80°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Palo Alto 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 Palo Alto averaged 1.8° warmer than the 1900s. The biggest change is in August (+2.2°). The shift is larger than in 89% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Palo Alto’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 60°. July is the most reliable, staying within 6°.
Common questions about Palo Alto’s climate
What is the coldest month in Palo Alto?
December, with a typical high of 59° and a low of 40°.
What is the hottest month in Palo Alto?
August, with a typical high of 80° and a low of 55°. About 12 days a year reach 90°.
How much snow does Palo Alto get?
Almost none. A normal year brings 0.0 inches.
When is the first frost in Palo Alto?
In half of years the first 32° night comes by December 7, and the last spring frost by February 1.
What is the rainiest month in Palo Alto?
January, with 4.1 inches of rain and melted snow. The year totals 21 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Palo Alto itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Palo Alto, CA (3 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.