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Costa Mesa, California weather

United States · America/Los_Angeles · 33.64, -117.92

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Costa Mesa, California 7 day forecast

A week of highs, lows, rain chances, wind, and UV for Costa Mesa, California, with a plain note about how much to trust each day.

The week at a glance

No day this week currently shows a strong rain signal.

Source updated: 4:36:52 PM · WeatherSignal checked: 4:36:52 PM

Source: Open-Meteo (national weather-service models)

  1. Today

    Clear sky

    95° / 80°

    Rain:
    0% · 0.00″
    Wind:
    20 mph
    UV:
    5.9
    Sun:
    11:00 PM to 11:00 AM

    High confidence: temperatures should be close, timing may shift by an hour or two.

  2. Tomorrow

    Mainly clear

    91° / 74°

    Rain:
    0% · 0.00″
    Wind:
    17 mph
    UV:
    5.9
    Sun:
    11:00 PM to 11:00 AM

    High confidence: temperatures should be close, timing may shift by an hour or two.

  3. Sunday, Oct 18

    Mainly clear

    84° / 68°

    Rain:
    0% · 0.00″
    Wind:
    11 mph
    UV:
    6.0
    Sun:
    11:00 PM to 11:00 AM

    Moderate confidence: the pattern is reliable, the details are not settled.

  4. Monday, Oct 19

    Clear sky

    80° / 68°

    Rain:
    0% · 0.00″
    Wind:
    12 mph
    UV:
    0.4
    Sun:
    11:00 PM to 11:00 AM

    Moderate confidence: the pattern is reliable, the details are not settled.

  5. Tuesday, Oct 20

    Clear sky

    74° / 67°

    Rain:
    0% · 0.00″
    Wind:
    7 mph
    UV:
    0.0
    Sun:
    11:00 PM to 11:00 AM

    Lower confidence: a long range outlook, useful for planning direction, not for exact numbers.

  6. Wednesday, Oct 21

    Clear sky

    69° / 62°

    Rain:
    0% · 0.00″
    Wind:
    13 mph
    UV:
    0.0
    Sun:
    11:00 PM to 11:00 AM

    Lower confidence: a long range outlook, useful for planning direction, not for exact numbers.

  7. Thursday, Oct 22

    Clear sky

    66° / 60°

    Rain:
    0% · 0.00″
    Wind:
    6 mph
    UV:
    0.0
    Sun:
    11:00 PM to 11:00 AM

    Lower confidence: a long range outlook, useful for planning direction, not for exact numbers.

Forecast confidence drops the further out you look. Use days five through seven to decide whether to keep a plan flexible, not to schedule around an exact hour.

Planning your week in Costa Mesa, California

  • The warmest afternoon ahead is today, reaching about 95°F.
  • The coldest night ahead dips to about 60°F.
  • This is a dry stretch — most days show rain chances under 20%, good for outdoor plans.
  • The breeziest day looks like today, with sustained wind near 20 mph.
  • UV reaches 6 on the sunniest day — sunscreen is worth it if you will be outside around midday.

Common questions about Costa Mesa, California weather

How accurate is the Costa Mesa, California forecast?
The next 48 hours are usually reliable on temperature and sky cover, with timing that can shift by an hour or two. Days three and four are dependable for the overall pattern. Beyond that, treat the numbers as a planning direction rather than a promise — we label confidence on every day so you can judge for yourself.
What is the best day this week in Costa Mesa, California?
No day in the current outlook has a rain chance above 40%, so conditions look favorable for outdoor plans across the week.
Where does this forecast come from?
Forecast values come from national weather model data, and official warnings come from the National Weather Service. We show the source and the last-updated time on every page, and we never invent a number the source did not publish — missing measurements are hidden, not guessed.
How often is this page updated?
The forecast refreshes whenever the source model publishes new data, typically several times a day. The freshness note near the top of the page shows exactly when the numbers you are looking at were issued.

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