Climateby Month

Costa Mesa, CA climate by month

NOAA 1991-2020 normals · 100 ft elevation · also covers Laguna Beach

Summers in Costa Mesa are warm; winters are mild. Highs peak at 85°F in August and fall to 68°F in December. The wettest month is January (about 7 wet days) and the driest is August (about 0). The most comfortable time to visit is May.

Warmest month
85°F
August normal high
Coldest month
48°F
December normal low
Wet days a year
35
9.4 in of precipitation
Muggy days a year
6
dew point 65°F or higher

How warm is Costa Mesa?

Normal highs range from 68°F in December to 85°F in August.

40°50°60°70°80°90° January: normal high 69°F (21°C), low 49°F (9°C) February: normal high 69°F (21°C), low 50°F (10°C) March: normal high 71°F (22°C), low 52°F (11°C) April: normal high 73°F (23°C), low 54°F (12°C) May: normal high 75°F (24°C), low 58°F (14°C) June: normal high 78°F (26°C), low 61°F (16°C) July: normal high 83°F (28°C), low 65°F (18°C) August: normal high 85°F (29°C), low 65°F (18°C) 85° 65° September: normal high 84°F (29°C), low 64°F (18°C) October: normal high 79°F (26°C), low 59°F (15°C) November: normal high 74°F (23°C), low 53°F (12°C) December: normal high 68°F (20°C), low 48°F (9°C) 68° 48° JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Costa Mesa?

January has the most wet days (about 7); the year brings about 9.4 in of precipitation.

January: 7 wet days 7 February: 7 wet days March: 5 wet days April: 3 wet days May: 2 wet days June: 1 wet days July: 1 wet days August: 0 wet days 0 September: 1 wet days October: 2 wet days November: 3 wet days December: 6 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How humid is Costa Mesa?

Muggy days peak in August, at about 3 days.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 0 muggy days June: 0 muggy days July: 2 muggy days August: 3 muggy days 3 September: 2 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at J. Wayne Apt-Orange Co Apt, 4.0 mi NE of the city center.

How much daylight?

Daylight ranges from about 10.0 hours in December to 14.4 hours in June.

January: 10.2 hours of daylight February: 11.0 hours of daylight March: 12.0 hours of daylight April: 13.0 hours of daylight May: 13.9 hours of daylight June: 14.3 hours of daylight 14.3 July: 14.1 hours of daylight August: 13.4 hours of daylight September: 12.4 hours of daylight October: 11.3 hours of daylight November: 10.4 hours of daylight December: 10.0 hours of daylight 10.0 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Costa Mesa, 1991-2020
MonthHighLowPrecip.Wet daysMuggy daysDaylight
January 69°F49°F 2.2 in7 0 10.2 h
February 69°F50°F 2.4 in7 0 11.0 h
March 71°F52°F 1.3 in5 0 12.0 h
April 73°F54°F 0.6 in3 0 13.0 h
May 75°F58°F 0.2 in2 0 13.9 h
June 78°F61°F 0.07 in1 0 14.3 h
July 83°F65°F 0.02 in1 2 14.1 h
August 85°F65°F 0.0 in0 3 13.4 h
September 84°F64°F 0.1 in1 2 12.4 h
October 79°F59°F 0.3 in2 0 11.3 h
November 74°F53°F 0.6 in3 0 10.4 h
December 68°F48°F 1.6 in6 0 10.0 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Costa Mesa

By our comfort score, the best month is May.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 702040
Feb 711841
Mar 792331
Apr 832211
May 882512
Jun 831901
Jul 62504
Aug 55307
Sep 56607
Oct 651415
Nov 732022
Dec 732230

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Costa Mesa

Costa Mesa is frost-free: NOAA's 1991-2020 normals record no nights at 32°F or below at Santa Ana John Wayne Airport.

Station: Santa Ana John Wayne Airport (USW00093184), NOAA 1991-2020 freeze probabilities. Frost dates for every city in California.

Hottest and coldest readings, 1991-2020

The highest reading was 114°F (July 6, 2018); the lowest was 25°F (December 10, 1998).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Costa Mesa

Similar climates elsewhere

Also covers

Laguna Beach uses the same temperature and rain stations as Costa Mesa, so its monthly numbers are the ones on this page.

Where the numbers come from

  • Temperature: Santa Ana Fire Stn (USC00047888), 7.7 mi NNE of the city center, 135 ft . NOAA normals and daily records, 1991-2020.
  • Rain, snowfall and snow depth: Newport Beach Harbor (USC00046175), 3.3 mi SE of the city center, 10 ft (90 ft lower than the city). NOAA normals and daily records, 1991-2020.
  • Frost dates: Santa Ana John Wayne Airport (USW00093184), 4.0 mi NE of the city center, 54 ft . NOAA normals and daily records, 1991-2020.
  • Humidity and wind by hour and cloud cover: Los Angeles Intl Airport (USW00023174), 34 mi NW of the city center, 97 ft . NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: J. Wayne Apt-Orange Co Apt (722977-93184), 4.0 mi NE of the city center, 43 ft (57 ft lower than the city). Hourly observations, 1991-2020.

Distances from the city center (USGS). Methodology · Report an error