Costa Mesa, CA

Climate overview — based on NOAA 1991-2020 normals from SANTA ANA JOHN WAYNE AP, CA US.

BSh Semi-arid (hot) climate 10a USDA hardiness Zone 10a

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

Costa Mesa has an annual average temperature of 64.9°F with about 11.2 inches of precipitation per year. The warmest month is August (average high 80.4°F), and the coldest is December (average low 48.3°F). February is typically the wettest month (2.64 in) and June the driest (0.01 in).

Pleasant months
9 / 12
avg high 65–80°F, low ≥ 50°F
Annual swing
16.4°F
warmest to coldest month
Heating need
936
Cooling need
906

Best time to visit Costa Mesa

Full guide →

Climate change signal

All-time records →

166 of 366 (45.4%) of Costa Mesa'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.

1990s
8
2000s
120
2010s
157
2020s
81

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 67.0°F 48.6°F 57.8°F 2.59 in 6
February 66.7°F 50.1°F 58.4°F 2.64 in 7
March 67.7°F 52.3°F 60.0°F 1.62 in 6
April 70.2°F 54.9°F 62.6°F 0.52 in 4
May 71.3°F 59.3°F 65.3°F 0.27 in 2
June 74.1°F 62.6°F 68.3°F 0.01 in 1
July 78.9°F 66.2°F 72.5°F 0.04 in 1
August 80.4°F 67.1°F 73.8°F 0.01 in 0
September 79.9°F 65.0°F 72.5°F 0.10 in 1
October 76.5°F 59.2°F 67.8°F 0.54 in 3
November 71.9°F 53.3°F 62.6°F 0.80 in 5
December 66.5°F 48.3°F 57.4°F 2.04 in 7

Climate twins of Costa Mesa

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

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