Climate and monthly weather forecastCosta Mesa, CA
Climate and monthly weather forecast
Weather in January
January, like December, in Costa Mesa, California, is another comfortable winter month, with temperature in the range of an average low of 53.6°F (12°C) and an average high of 64.4°F (18°C). Costa Mesa starts January with an average high-temperature of a still comfortable 64.4°F (18°C), hinting at a minimal fluctuation from December. Weather in January »Weather in February
February, the last month of the winter in Costa Mesa, is another comfortable month, with an average temperature ranging between max 63.3°F (17.4°C) and min 52.3°F (11.3°C). February welcomes an average high-temperature of a still comfortable 63.3°F (17.4°C), not much different from the preceding month. Weather in February »Weather in March
The first month of the spring, March, is also an enjoyable month in Costa Mesa, California, with temperature in the range of an average low of 53.4°F (11.9°C) and an average high of 64.8°F (18.2°C). On the advent of March, Costa Mesa's average high-temperature exhibits a minor adjustment to a still comfortable 64.8°F (18.2°C) from February's 63.3°F (17.4°C). Weather in March »Weather in April
April, the same as March, is another comfortable spring month in Costa Mesa, California, with an average temperature varying between 66.6°F (19.2°C) and 54.9°F (12.7°C). The high-temperature average in April for Costa Mesa is a still enjoyable 66.6°F (19.2°C), staying closely aligned with March's conditions. Weather in April »Weather in May
The last month of the spring, May, is another comfortable month in Costa Mesa, California, with temperature in the range of an average low of 56.8°F (13.8°C) and an average high of 67.6°F (19.8°C). Costa Mesa experiences a transition to a still comfortable 67.6°F (19.8°C) in average high-temperatures with the arrival of May, not greatly differing from April's 66.6°F (19.2°C). Weather in May »Weather in June
The first month of the summer, June, is a pleasant month in Costa Mesa, California, with an average temperature ranging between max 70.7°F (21.5°C) and min 58.6°F (14.8°C). The transition into June marks the average high-temperature at a pleasant 70.7°F (21.5°C), differing minimally from May's 67.6°F (19.8°C). Weather in June »Weather in July
July in Costa Mesa, California, is a warm summer month, with temperature in the range of an average high of 75°F (23.9°C) and an average low of 63.5°F (17.5°C). Costa Mesa records an average high-temperature of a moderately hot 75°F (23.9°C) in July, closely mirroring the climate of the previous month. Weather in July »Weather in August
August, the last month of the summer in Costa Mesa, is also a moderately hot month, with an average temperature fluctuating between 64.9°F (18.3°C) and 76.6°F (24.8°C). The highest temperatures are recorded in August, with averages reaching a high of 76.6°F (24.8°C) and a low of 64.9°F (18.3°C). Weather in August »Weather in September
The first month of the autumn, September, is also a moderately hot month in Costa Mesa, California, with an average temperature ranging between max 76.1°F (24.5°C) and min 64.2°F (17.9°C). Costa Mesa ushers in September with an average high-temperature of a still moderately hot 76.1°F (24.5°C), showing a close resemblance to the previous month. Weather in September »Weather in October
October, like September, is an agreeable autumn month in Costa Mesa, California, with an average temperature ranging between min 62.1°F (16.7°C) and max 73°F (22.8°C). The onset of October marks an average high-temperature of a pleasant 73°F (22.8°C), hardly differing from September's 76.1°F (24.5°C). Weather in October »Weather in November
November, the last month of the autumn in Costa Mesa, is also an agreeable month, with an average temperature varying between 68.5°F (20.3°C) and 57.9°F (14.4°C). Costa Mesa's average high-temperature in November is a still pleasant 68.5°F (20.3°C), indicating a subtle variation from October. Weather in November »Weather in December
December, the first month of the winter in Costa Mesa, is also an enjoyable month, with an average temperature fluctuating between 53.1°F (11.7°C) and 62.4°F (16.9°C). The lowest temperatures are recorded in December, with averages reaching a high of 62.4°F (16.9°C) and a low of 53.1°F (11.7°C). Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Costa Mesa, CA
The warmest month (with the highest average high temperature) is August (76.6°F).
The month with the lowest average high temperature is December (62.4°F).
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (52.3°F).
Average pressure
Costa Mesa, CA
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.05"Hg - Average pressure in March:
30.03"Hg - Average pressure in April:
29.97"Hg - Average pressure in May:
29.93"Hg - Average pressure in June:
29.89"Hg
- Average pressure in July:
29.92"Hg - Average pressure in August:
29.9"Hg - Average pressure in September:
29.89"Hg - Average pressure in October:
29.95"Hg - Average pressure in November:
30.03"Hg - Average pressure in December:
30.07"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.89"Hg).
Average wind speed
Costa Mesa, CA
- Average wind speed in January:
5.5mph - Average wind speed in February:
5.8mph - Average wind speed in March:
6.2mph - Average wind speed in April:
6.6mph - Average wind speed in May:
6.5mph - Average wind speed in June:
5.8mph
- Average wind speed in July:
5.6mph - Average wind speed in August:
5.3mph - Average wind speed in September:
5.3mph - Average wind speed in October:
5.2mph - Average wind speed in November:
5.5mph - Average wind speed in December:
5.7mph
The windiest month (with the highest average wind speed) is April (6.6mph).
The calmest month (with the lowest average wind speed) is October (5.2mph).
Average humidity
Costa Mesa, CA
The month with the highest relative humidity is June (74%).
The month with the lowest relative humidity is November (59%).
Average rainfall
Costa Mesa, CA
- Average rainfall in January:
0.39" - Average rainfall in February:
0.51" - Average rainfall in March:
0.43" - Average rainfall in April:
0.28" - Average rainfall in May:
0.12" - Average rainfall in June:
0.04"
The wettest month (with the highest rainfall) is December (0.79").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days
Costa Mesa, CA
- Average rainfall days in January:
4.2 days - Average rainfall days in February:
5.3 days - Average rainfall days in March:
6.6 days - Average rainfall days in April:
5.3 days - Average rainfall days in May:
3.4 days - Average rainfall days in June:
1.6 days
- Average rainfall days in July:
4.4 days - Average rainfall days in August:
2.8 days - Average rainfall days in September:
3.3 days - Average rainfall days in October:
3.2 days - Average rainfall days in November:
4.4 days - Average rainfall days in December:
6.2 days
The month with the highest number of rainy days is March (6.6 days).
The month with the least rainy days is June (1.6 days).
Average daylight / Average sunshine
Costa Mesa, CA
- Average daylight in January:
10h and 12min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 0min - Average daylight in May:
13h and 54min - Average daylight in June:
14h and 24min
- Average daylight in July:
14h and 6min - Average daylight in August:
13h and 24min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 18min - Average daylight in November:
10h and 24min - Average daylight in December:
10h and 0min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in January:
6h and 42min - Average sunshine in February:
6h and 48min - Average sunshine in March:
8h and 42min - Average sunshine in April:
10h and 54min - Average sunshine in May:
11h and 0min - Average sunshine in June:
11h and 42min
- Average sunshine in July:
11h and 54min - Average sunshine in August:
12h and 0min - Average sunshine in September:
10h and 30min - Average sunshine in October:
8h and 24min - Average sunshine in November:
7h and 6min - Average sunshine in December:
6h and 36min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).
Average sunshine days
Costa Mesa, CA
- Average sunshine days in January:
25.8 days - Average sunshine days in February:
20.5 days - Average sunshine days in March:
22.8 days - Average sunshine days in April:
22 days - Average sunshine days in May:
23.4 days - Average sunshine days in June:
26.5 days
- Average sunshine days in July:
24.8 days - Average sunshine days in August:
25.8 days - Average sunshine days in September:
24.5 days - Average sunshine days in October:
25.3 days - Average sunshine days in November:
23.9 days - Average sunshine days in December:
23.6 days
The month with the most sunshine days is June (26.5 days).
The month with the least sunshine days is February (20.5 days).
Average UV index
Costa Mesa, CA
The months with the highest UV index are July, August and September (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 4).
Average cloud cover
Costa Mesa, CA
The months with the most cloud cover are March and December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 8).
Average visibility
Costa Mesa, CA
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





