Costa Mesa, CA weather in August
In August, Costa Mesa sees highs around 85°F and lows around 65°F: warm and dry. Rain is rare. It is one of the warmest months in Costa Mesa.
- Normal high
- 85°F
- Normal low
- 65°F
- Wet days
- 0
- 0.0 in total
- Muggy days
- 3
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 84°F | 85°F |
| Normal low | 65°F | 65°F |
| Chance of a wet day | 1% | 1% |
| Sunrise / sunset | 6:03 am / 7:52 pm | 6:25 am / 7:18 pm |
| Daylight | 13.8 h | 12.9 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).
A typical August day
- 6 am67°Fdew point 62°F
- 9 am72°Fdew point 62°F
- Noon74°Fdew point 62°F
- 3 pm73°Fdew point 61°F
- 6 pm69°Fdew point 61°F
- 9 pm67°Fdew point 61°F
NOAA hourly normals (local standard time) from Los Angeles Intl Airport (34 mi away); average wind 8 mph; clear or few clouds in 55% of daytime hours, mostly cloudy or overcast in 18%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F3 of 31
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph27 of 31
- Hot dayshigh 90°F or more7 of 31
- Muggy daysdaily mean dew point 65°F or more3 of 31
- Wet daysat least 0.01 in of rain or melted snow0 of 31
- Notable rainat least 0.10 in0 of 31
- Freezing nightslow 32°F or below0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 0.0 in; a dry August brings about 0.0 in and a wet one about 0.0 in (25th and 75th percentiles). Days with half an inch or more are rare.
How August varies from year to year
- Warmest August, 1991-20202007: average high 89°F
- Coolest August2002: average high 81°F
- Wettest August2014: 0.02 in
- Driest August1991: no measurable precipitation
- Highest reading106°F (August 18, 2020)
- Lowest reading52°F (August 12, 1999)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 83°F | 85°F | 84°F |
| Normal low | 65°F | 65°F | 64°F |
| Wet days | 1 | 0 | 1 |
| Comfortable days | 5 | 3 | 6 |
| Daylight | 14.1 h | 13.4 h | 12.4 h |
Highs change by +2°F from July and -1°F into September.
Nearby alternatives in August
- Warmer: Corona, CA26 mi · high 96°F · 0 wet days
- Cooler: Torrance, CA28 mi · high 77°F · 0 wet days
How Costa Mesa ranks in August
- Normal high214th warmest of 378 cities; 34th of 60 in California
- Wet days18th driest of 378
- Comfortable days154th most of 341
What to pack for Costa Mesa in August
- Light, breathable clothing – highs near 85°F and about 3 muggy days
- A swimsuit – about 27 beach days
Heating and cooling
August has 0 heating degree days and 308 cooling degree days (base 65°F), 14% of the year's total heating and cooling demand.
Questions
How hot is Costa Mesa in August?
The normal high is 85°F and the normal low is 65°F. From 1991 to 2020 the hottest August reading was 106°F (August 18, 2020).
Does it rain a lot in Costa Mesa in August?
About 0 days in August have at least 0.01 in of precipitation, and the normal total is 0.00 in. The wettest August in 1991-2020 was in 2014 (0.02 in); the driest was in 1991, with no measurable precipitation.
Is August a good time to visit Costa Mesa?
August ranks 12th of 12 months on our comfort score for Costa Mesa (55 out of 100). It has about 3 comfortable days and about 7 days at 90°F or hotter. The best month is May.
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.