San Marcos, CA

Climate overview — based on NOAA 1991-2020 normals from ESCONDIDO #2, CA US.

BSh Semi-arid (hot) climate 9b USDA hardiness Zone 9b

Year-round temperatures (°F)

40° 50° 60° 70° 80° 90° J F M A M J J A S O N D
Avg high Avg low

Climate summary

San Marcos has an annual average temperature of 65.8°F with about 14.5 inches of precipitation per year. The warmest month is August (average high 89.0°F), and the coldest is December (average low 43.8°F). February is typically the wettest month (3.57 in) and August the driest (0.06 in).

Pleasant months
2 / 12
avg high 65–80°F, low ≥ 50°F
Annual swing
21.3°F
warmest to coldest month
Heating need
1,056
Cooling need
1,344

Best time to visit San Marcos

Full guide →

Climate change signal

All-time records →

128 of 366 (35%) of San Marcos's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.

1970s
18
1980s
64
1990s
75
2000s
51
2010s
85
2020s
73

Bars: number of all-time daily heat records still standing that were set in each decade.

Monthly averages

Month Avg High Avg Low Avg Temp Precipitation Snow Rainy days
January 68.8°F 44.8°F 56.8°F 3.19 in 6
February 68.7°F 45.9°F 57.3°F 3.57 in 7
March 71.0°F 48.9°F 59.9°F 2.20 in 6
April 74.2°F 51.8°F 63.0°F 0.99 in 4
May 76.7°F 56.4°F 66.6°F 0.35 in 3
June 81.9°F 60.2°F 71.1°F 0.09 in 1
July 87.2°F 64.4°F 75.8°F 0.12 in 1
August 89.0°F 65.3°F 77.2°F 0.06 in 0
September 86.9°F 63.1°F 75.0°F 0.16 in 1
October 80.8°F 57.3°F 69.1°F 0.57 in 2
November 74.6°F 49.1°F 61.9°F 1.08 in 4
December 68.0°F 43.8°F 55.9°F 2.14 in 6

Climate twins of San Marcos

Why these? →

The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).

Frost dates
Last spring / first fall frost
All-time records
Hottest, coldest, wettest
Planting calendar
What to plant, and when

Compare San Marcos to another city