Costa Mesa, California weather
United States · America/Los_Angeles · 33.64, -117.92
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Costa Mesa, CA Weather Today
Current conditions, hourly and 7 day forecast, official severe weather alerts, and air quality for Costa Mesa, California. Every section shows where the data came from and when it was last checked.
Your briefing — take action
Costa Mesa, California
- Right now
- Heat Advisory in effect for San Diego County Coastal Areas; Orange County Coastal.Official warning
- Next few hours
- No rain in the forecast for the next few hours.Forecast
- Your day
- Best outdoor window: 6 AM to 10 AM.Our reading
What officials say to do
- Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.
- Take extra precautions when outside.
- Wear lightweight and loose fitting clothing.
- Try to limit strenuous activities to early morning or evening.
- Take action when you see symptoms of heat exhaustion and heat stroke.
Wording from NWS San Diego CA. Read the official warning
What happens next
- NowHeat Advisory covers San Diego County Coastal Areas; Orange County Coastal.Official warning
- NextOfficial warning runs until 5:15 AM.Official warning
Official warnings for this location come from NOAA / National Weather Service. Lines marked Our reading are WeatherSignal’s reading of the measurements and forecast, not an official statement.
Costa Mesa, California
95°
Clear sky
Feels like 95° · High 95° · Low 94°
Clear sky here right now. Nothing falling.
Hot and clear tonight. 95° right now. Overnight low around 94°. Tomorrow starts clear sky. Sunrise is at 11:00 PM.
- Overnight low 94°
- Sunrise 11:00 PM
- Rain overnight 0%
Next few hours
Now
95°
—
4 PM
94°
—
5 PM
93°
—
6 PM
91°
—
7 PM
89°
—
- Rain chance
- 0%
- Wind
- 16 mph ENE
- Humidity
- 24%
- Air quality
- No reading
Source updated: 10:49:57 PM · WeatherSignal checked: 10:49:57 PM
What matters today
Six quick answers for Costa Mesa. Tap Why? on any of them to see the reasoning.
Umbrella
Nah (Good)
Best time
7 AM (Good)
Dog walk
3 AM (Good)
Car wash
Go for it (Good)
Cookout
Green light (Good)
Windows
Keep them up (Not good)
Today's Signal
Mixed day
60/100
A mixed day: the heat, the wind and poor visibility will get in the way of outdoor plans.
Feels like 95° · Wind 16 mph · Visibility 0.0 mi · Active Heat Advisory
Today is about 18° warmer than the rest of the week.
See exactly how this number was worked out
Every location starts at 100. Points come off for heat, cold, rain, wind, UV, humidity, poor visibility, and any official alert. Nothing is ever added back.
- Starting score100
- Feels like 95°: hot-20
- Wind 16 mph-4
- Visibility 0.0 mi-10
- Active Heat Advisory-6
- Final Signal60
Next 12 hours
Steady conditions, but the temperature swings about 17° across the next 12 hours.
- 4 PMWarmest stretch · 94°
- 11 PMSunrise
- 3 AMCoolest stretch · 77°
- 4 PM—94 degrees, 0 percent chance of rain
- 5 PM—93 degrees, 0 percent chance of rain
- 6 PM—91 degrees, 0 percent chance of rain
- 7 PM—89 degrees, 0 percent chance of rain
- 8 PM—87 degrees, 0 percent chance of rain
- 9 PM—86 degrees, 0 percent chance of rain
- 10 PM—84 degrees, 0 percent chance of rain
- 11 PM—82 degrees, 0 percent chance of rain
- 12 AM—81 degrees, 0 percent chance of rain
- 1 AM—80 degrees, 0 percent chance of rain
- 2 AM—78 degrees, 0 percent chance of rain
- 3 AM—77 degrees, 0 percent chance of rain
The line is temperature by hour. The number under each hour is the chance of rain. Scroll sideways for the full 12 hours.
Next change
It keeps cooling down overnight
Temperatures fall from about 94° to 77° over the next 12 hours. There is no meaningful rain signal in the next several hours.
WeatherSignal NOW: Costa Mesa, California
One number for everything happening around you, from 0 to 100.
92
NORMAL
Nothing here needs your attention right now.
Tap any line to see exactly what added or subtracted points. Every rule is published on our methodology page. This is an informational signal, not a safety rating: official warnings always come first.
What this means
Generated from the forecast values above using fixed rules: not an AI guess.
- A Heat Advisory issued by NWS San Diego CA is active for San Diego County Coastal Areas.
- No significant precipitation is expected in the next 24 hours.
Next 24 hours
Will it rain during your commute? When does the storm arrive?
See all 47 hours (2 days) — free
| Time | Condition | Temp | Feels | Precip % | Amount | Wind | Humidity |
|---|---|---|---|---|---|---|---|
| 4 PM | Clear sky | 94° | 94° | 0% | 0.00″ | 13 E | 25% |
| 5 PM | Clear sky | 93° | 93° | 0% | 0.00″ | 12 E | 25% |
| 6 PM | Clear sky | 91° | 91° | 0% | 0.00″ | 11 ENE | 26% |
| 7 PM | Clear sky | 89° | 89° | 0% | 0.00″ | 14 NE | 27% |
| 8 PM | Clear sky | 87° | 87° | 0% | 0.00″ | 15 N | 28% |
| 9 PM | Clear sky | 86° | 86° | 0% | 0.00″ | 14 NNW | 30% |
| 10 PM | Clear sky | 84° | 84° | 0% | 0.00″ | 15 NW | 32% |
| 11 PM | Clear sky | 82° | 82° | 0% | 0.00″ | 15 NW | 34% |
| 12 AM | Clear sky | 81° | 81° | 0% | 0.00″ | 15 NW | 35% |
| 1 AM | Clear sky | 80° | 80° | 0% | 0.00″ | 14 NW | 36% |
| 2 AM | Clear sky | 78° | 78° | 0% | 0.00″ | 15 NNW | 36% |
| 3 AM | Clear sky | 77° | 77° | 0% | 0.00″ | 13 NNW | 36% |
| 4 AM | Clear sky | 77° | 77° | 0% | 0.00″ | 11 N | 36% |
| 5 AM | Clear sky | 76° | 76° | 0% | 0.00″ | 8 NNE | 38% |
| 6 AM | Clear sky | 75° | 75° | 0% | 0.00″ | 7 ENE | 36% |
| 7 AM | Clear sky | 73° | 73° | 0% | 0.00″ | 7 ESE | 41% |
| 8 AM | Clear sky | 75° | 75° | 0% | 0.00″ | 8 E | 44% |
| 9 AM | Clear sky | 81° | 81° | 0% | 0.00″ | 11 NNE | 36% |
| 10 AM | Clear sky | 86° | 86° | 0% | 0.00″ | 12 ESE | 27% |
| 11 AM | Partly cloudy | 88° | 88° | 0% | 0.00″ | 11 SSE | 34% |
| 12 PM | Mainly clear | 88° | 93° | 0% | 0.00″ | 9 SW | 51% |
| 1 PM | Partly cloudy | 88° | 94° | 0% | 0.00″ | 8 WSW | 55% |
| 2 PM | Overcast | 87° | 92° | 0% | 0.00″ | 9 WSW | 57% |
| 3 PM | Partly cloudy | 84° | 86° | 0% | 0.00″ | 9 W | 53% |
7-day forecast
Confidence decreases the further out you look.
Today
Clear sky
95° / 94°
- Precip:
- 0% · 0.00″
- Wind:
- 16 mph
- UV:
- 3.1
- Sun:
- 11 PM to 11 AM
Sat, Oct 17
Clear sky
93° / 73°
- Precip:
- 0% · 0.00″
- Wind:
- 15 mph
- UV:
- 5.9
- Sun:
- 11 PM to 11 AM
Sun, Oct 18
Clear sky
83° / 69°
- Precip:
- 0% · 0.00″
- Wind:
- 11 mph
- UV:
- 6.0
- Sun:
- 11 PM to 11 AM
Mon, Oct 19
Clear sky
78° / 68°
- Precip:
- 0% · 0.00″
- Wind:
- 10 mph
- UV:
- 0.4
- Sun:
- 11 PM to 11 AM
Tue, Oct 20
Clear sky
74° / 67°
- Precip:
- 0% · 0.00″
- Wind:
- 7 mph
- UV:
- 0.0
- Sun:
- 11 PM to 11 AM
Lower confidence: long-range outlook, not a certainty.
Wed, Oct 21
Clear sky
69° / 62°
- Precip:
- 0% · 0.00″
- Wind:
- 13 mph
- UV:
- 0.0
- Sun:
- 11 PM to 11 AM
Lower confidence: long-range outlook, not a certainty.
Thu, Oct 22
Clear sky
66° / 60°
- Precip:
- 0% · 0.00″
- Wind:
- 6 mph
- UV:
- 0.0
- Sun:
- 11 PM to 11 AM
Lower confidence: long-range outlook, not a certainty.
Forecasts describe likely conditions, not guaranteed outcomes. Official warnings from your national weather service always take precedence over anything shown here.
Costa Mesa hourly weather
Hour by hour, out to eight days ahead.
Costa Mesa 7 day forecast
Highs, lows and rain chance for the week.
Air quality detail
Pollutants, category, and official guidance.