Costa Mesa receives its highest rainfall in Feb, while humidity peaks in spring.
🌧️ Wettest:Feb — 79 mm☀️ Driest:Jul — 1 mm
💧 Humidity peaks at 77% in May · annual avg 73%
🌍 Climate Summary
Avg Annual Temp:65.7°F
Avg Annual Rainfall:342 mm
Avg Humidity:73%
Data Period:1981 – 2025
Costa Mesa Climate Overview
Costa Mesa has a warm subtropical climate with warm summers and mild winters.
Temperatures peak in Sep and drop to their lowest in Jan,
while rainfall is highest during winter months.
Humidity remains moderate throughout the year, especially in spring, creating warm and humid conditions.
📈 Yearly Trends
The warmest year in Costa Mesa's recorded history was 2014
(avg: 68.9°F),
while the coldest year was 1982
(avg: 63.7°F),
based on annual average temperatures.
📊 Key Climate Trends
🌡️ Costa Mesa's temperature has remained relatively stable over the past decade
📈 Minimum temperatures show a slight warming trend in recent years
🌧️ Rainfall varies year-to-year without a clear long-term trend
🌡️ Annual Temperature Trend
View Range:
Average annual high/low · Last 10 years · °F
Costa Mesa's temperatures has remained relatively stable over the past decade.
The highest recorded temperature reached
96.4°F in Sep 1988,
while the lowest dropped to
40.5°F in Dec 1990.
🌧️ Annual Precipitation
View Range:
Total annual precipitation · Last 10 years · mm/year
Annual rainfall in Costa Mesa shows noticeable variation. Rainfall varies year-to-year without a clear long-term trend.
Based on 45 years of data (1981–2025), Sep is typically the hottest month in Costa Mesa, California, with average high temperatures around 83.8°F.
What is the coldest month in Costa Mesa?▼
Jan is the coldest month in Costa Mesa, with average low temperatures around 48.3°F.
What is the rainiest month in Costa Mesa?▼
Feb receives the most rainfall with approximately 79 mm, while Jul is the driest with 1 mm.
What was the highest temperature ever recorded in Costa Mesa?▼
The highest recorded temperature was 96.4°F in Sep 1988. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in Costa Mesa?▼
The lowest recorded temperature was 40.5°F in Dec 1990.
How many years of data does this page cover?▼
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
How much sunlight does Costa Mesa get?▼
Costa Mesa receives the most sunlight in Jul with an average solar radiation of 7.25 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability in California.
Where does this weather data come from?▼
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
📚 Data Source
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.