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CheckWeather USCosta Mesa
Forecast confidence: High · models disagree by 3°F

Costa Mesa weather

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Mostly clear,rain likely tomorrow

NWS, the American and the European model agree on a high near 82° in Costa Mesa today. Tomorrow looks drizzle around 80°, with a 92% chance of rain, and the models disagree, so treat it as uncertain.

82°63°
80°70°
86°70°
87°72°
90°74°
86°74°
Todaymodels agreeTomorrowsplit ±11°Mondaysplit ±7°Tuesdaysplit ±8°Wednesdaysplit ±9°Thursdaysplit ±8°
NWSNational Blend (NBM)
80°
Mostly clear
Today 80°·Low 64°·Rain 1%
AmericanNOAA GFS
83°
Partly cloudy
Today 83°·Low 60°·Rain 1%
EuropeanECMWF
82°
Clear
Today 82°·Low 65°·Rain 31%

The weather map: all three models at once

NWS, American, European side by side around Costa Mesa and nearby towns.Live rain radar →
Loading the three model maps…

Next 14 hours

consensus of the three models

14-day forecast

where the models agree, and where they split
Today
Mostly clear
82° 63°
models agree
Tomorrow
Drizzle
80° 70°
±11°
Mon
Mostly clear
86° 70°
±7°
Tue
Cloudy
87° 72°
±8°
Wed
Mostly clear
90° 74°
±9°
Thu
Mostly clear
86° 74°
±8°
Fri
Mostly clear
81° 71°
models agree
Sat
Mostly clear
78° 70°
models agree
Sun
Cloudy
80° 68°
models agree
Mon
Clear
79° 68°
±5°
Tue
Light drizzle
82° 68°
±12°
Wed
Drizzle
83° 72°
±8°
Thu
Light drizzle
81° 71°
models agree
Fri
Mostly clear
81° 70°
±6°

Costa Mesa, CA is at its warmest in Jul (average highs near 76°F) and coldest in Jan (lows around 48°F), with roughly 26 in of precipitation across the year. Below, compare what NWS, American, European forecast for Costa Mesa right now, and see exactly where they disagree.

We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in United States before you trust any single number.

Costa Mesa climate by month

average daytime high and overnight low across a typical year
Jan
61°
48°
Feb
60°
48°
Mar
60°
49°
Apr
64°
52°
May
66°
56°
Jun
70°
60°
Jul
76°
62°
Aug
76°
63°
Sep
75°
62°
Oct
74°
58°
Nov
69°
53°
Dec
65°
50°

Which forecast is most accurate in Costa Mesa?

CheckWeather Score — graded against the weather that actually happened
ProviderCheckWeather Score🌡 Temp💨 Wind🌧 RainRun by
European logo
European ★ Best
90
/100rank #1
75±2.5°F98±0.8 mph100100% hitECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American logo
American
88
/100rank #2
71±2.9°F98±0.7 mph100100% hitNOAA / NCEP (United States)College Park, Maryland, USA

The CheckWeather Score blends temperature, wind and rain accuracy — each measured against ERA5 (the recorded weather) over the last 30 days across 1999 cities. Lower error means a higher score. See which forecast model is most accurate in United States, how we measure forecast accuracy, or which model each weather app uses.

Where the models disagree

temperature and rain, judged separately
DayTemperatureRain
Today±3°80° to 83°±30%1% to 31% chance
Tomorrow±11°75° to 86°±52%40% to 92% chance
Mon±7°83° to 90°±14%5% to 19% chance
Tue±8°84° to 92°±2%8% to 10% chance
Wed±9°86° to 94°±3%7% to 10% chance

The models often agree on temperature and still split on rain — and rain is usually what decides whether a plan survives. A wide rain range means the shower is genuinely uncertain, not that the forecast is wrong.

Sunrise and sunset in Costa Mesa

today, local time
Sunrise
06:28
Sunset
19:11
Daylight
12h 43m

Common questions

What's the weather in Costa Mesa today?
On this page we show what NWS, American, European each forecast for Costa Mesa today, side by side and updated live. When all three agree the forecast is reliable; when they split, we flag it so you know the day is genuinely less certain.
Will it rain in Costa Mesa today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Costa Mesa and flag the days where the models disagree on whether showers actually arrive, which is exactly when a single app can catch you out.
Which forecast is most accurate for Costa Mesa?
Over the last 30 days, the European model has been the most accurate for Costa Mesa (CheckWeather Score 90/100), ahead of the American at 88. We grade every model against the recorded weather. See the US accuracy scoreboard for the full method.
What is the warmest month in Costa Mesa?
July is typically the warmest month in Costa Mesa, with average highs around 76°F.
How cold does Costa Mesa get?
The coldest month in Costa Mesa is January, when overnight lows average about 48°F.
How much rain does Costa Mesa get?
Costa Mesa sees roughly 26 in of precipitation a year, with February usually the wettest month.

Nearby

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