Get the monthly weather forecast for Costa Mesa, CA, including daily high/low, historical averages, to help you plan ahead.

The weather in Costa Mesa in September is pleasantly warm and comfortable, with average highs of 82°F (28°C) and lows of 66°F (19°C).

September weather forecast in Costa Mesa · 1 September. Sunday. +24°. +21° · 2 September. Monday. +24°. +20° · 3 September. Tuesday. +24°. +21° · 4 September.

Partly cloudy skies. Low 47F. Winds light and variable. Record Low38°.

Check accurate weather in September in Costa Mesa (CA). Expect Costa Mesa September temperature around 27°C (81°F). Read clothing tips & recommended ...

September in Costa Mesa. Max. temperature +39.2°C. Min. temperature +13.6°C. Monthly precipitation 40.89mm. Wind speed 13.37m/s.

The clearest month of the year in Costa Mesa is September, during which on average the sky is clear, mostly clear, or partly cloudy 90% of the time. The ...

12:53 AM, 62 °F, 56 °F, 80 °%, CALM, 0 °mph, 0 °mph, 29.84 °in, 0.0 °in, Fair. 1:53 AM, 62 °F, 56 °F, 80 °%, CALM, 0 °mph, 0 °mph, 29.84 °in, 0.0 °in, Fair.

In the summer months, the hottest month of the year in Costa Mesa is September, with an average high of 80°F and average low of 64°F. In the winter months, the ...