La Mesa, CA climate
La Mesa has warm winters and pleasant summers, with very little rain. A typical July afternoon reaches 83°, a January night drops to 44°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in La Mesa feels like
Winter
Spring
Summer
Fall
La Mesa 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 | 69° | 44° | 2.4" | 0 | 7 | 0 | 53° – 61° |
| February | 68° | 46° | 2.6" | 0 | 8 | 0 | 53° – 62° |
| March | 70° | 48° | 1.9" | 0 | 7 | 0 | 54° – 65° |
| April | 72° | 51° | 0.9" | 0 | 4 | 0 | 57° – 65° |
| May | 74° | 55° | 0.3" | 0 | 3 | 0 | 60° – 69° |
| June | 78° | 58° | 0.1" | 0 | 1 | 0 | 64° – 72° |
| July | 83° | 62° | 0.0" | 0 | 1 | 0 | 69° – 78° |
| August | 86° | 64° | 0.0" | 0 | 0 | 0 | 71° – 78° |
| September | 85° | 61° | 0.1" | 0 | 1 | 0 | 69° – 77° |
| October | 80° | 56° | 0.5" | 0 | 3 | 0 | 64° – 73° |
| November | 74° | 48° | 1.1" | 0 | 4 | 0 | 55° – 65° |
| December | 68° | 44° | 1.9" | 0 | 7 | 0 | 53° – 59° |
| Year | 75° | 53° | 11.9" | 0.0" | 45 | 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 La Mesa
La Mesa gets 12 inches of rain and melted snow a year. February is the wettest month and August the driest. Rain or snow falls on about 45 days a year.
A year-round growing season
Heating and cooling a home in La Mesa
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In La Mesa, 49% of that work is heating and 51% 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.
La Mesa and its neighbors
La Mesa borders 5 towns with climate data. January nights across them vary by 2.2°. El Cajon has both the coldest January nights (43°) and the hottest July afternoons (85°). La Mesa’s January low is 44° and its July high 83°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How La Mesa 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 La Mesa averaged 2.2° warmer than the 1900s. The biggest change is in January (+3.1°). The shift is larger than in 97% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at La Mesa’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 54° to 65°. December is the most reliable, staying within 6°.
Common questions about La Mesa’s climate
What is the coldest month in La Mesa?
December, with a typical high of 68° and a low of 44°.
What is the hottest month in La Mesa?
August, with a typical high of 86° and a low of 64°. About 57 days a year reach 90°.
How much snow does La Mesa get?
Almost none. A normal year brings 0.0 inches.
When is the first frost in La Mesa?
Frost is uncommon. Only 73% of years see a night at 32° or below.
What is the rainiest month in La Mesa?
February, with 2.6 inches of rain and melted snow. The year totals 12 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for La Mesa itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Lakeside 2 E, CA (9 mi, snow) and El Cajon, CA (5 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.