Costa Mesa in Spring
In spring (March, April and May), Costa Mesa sees average daytime highs around 69°F and overnight lows near 55°F, with 2.8 in of rain over about 9 wet days across the season. It is the 3rd-warmest season and the 2nd-wettest season.
Over the season highs climb from about 65°F in early March to 71°F by late May. The sky is clear or mostly clear about 53% of the time across spring, and the air most often feels dry.
Spring is Costa Mesa's 3rd-best season to visit on our travel score. For the whole year in context, see Costa Mesa's year-round climate.
- Avg daytime high
- 69°F
- 3rd-warmest season
- Avg overnight low
- 55°F
- Rainfall
- 2.8 in
- 9 wet days
- Avg wind
- 6 mph
- Travel score
- 7.7
- 3rd-best season
- Months
- Mar · Apr · May
Temperature in Costa Mesa in Spring
Over the season highs climb from about 65°F in early March to 71°F by late May.
A typical spring day in Costa Mesa reaches about 69°F and drops to 55°F overnight. The warmest of the three months is May, the coolest March.
Costa Mesa weather by month
How the three spring months (March, April and May) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 64° / 49° | 2.8 | 5.2 | 10 | 6.8 |
| Feb | 65° / 50° | 3.1 | 6.1 | 10.7 | 6.7 |
| Mar | 66° / 53° | 1.8 | 5.1 | 11.7 | 7.0 |
| Apr | 69° / 55° | 0.7 | 2.6 | 12.8 | 7.9 |
| May | 71° / 58° | 0.3 | 1.5 | 13.7 | 8.3 |
| Jun | 74° / 61° | 0.1 | 0.3 | 14.2 | 9.1 |
| Jul | 79° / 64° | 0.1 | 0.4 | 14 | 9.0 |
| Aug | 81° / 65° | 0.0 | 0.1 | 13.2 | 8.9 |
| Sep | 80° / 64° | 0.1 | 0.5 | 12.2 | 8.8 |
| Oct | 76° / 60° | 0.6 | 1.9 | 11.2 | 8.8 |
| Nov | 70° / 54° | 0.7 | 2.4 | 10.3 | 8.1 |
| Dec | 65° / 49° | 1.9 | 4.9 | 9.8 | 6.9 |
Cloud cover in Spring
The sky is clear or mostly clear about 53% of the time across spring.
Chance of precipitation in Spring
Costa Mesa gets around 2.8 in of rain over 9 wet days across spring. The line is the day-by-day chance of measurable precipitation.
Humidity in Spring
Most of spring feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Spring
Winds average 6 mph across spring.
Sunrise & sunset in Spring
Daylight runs from about 11 h 12 min in early March to 14 hours by late May. The lit band spans sunrise to sunset each day.
Solar energy in Spring
Average shortwave solar energy reaching the ground each day across spring, about 6.4 kWh/m².
Is spring a good time to visit Costa Mesa?
Our two travel scores rate spring for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
spring is one of the better times to visit Costa Mesa for general sightseeing.
What to pack for Costa Mesa in Spring
From spring's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In spring, Costa Mesa sees daytime highs around 69°F and nights near 55°F. Pack sun protection. About 9 days see rain.
Sea temperature near Costa Mesa in Spring
The nearest coast averages about 61°F across spring — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 69°F and coldest in February near 59°F.
It's comfortable for a long swim from Jul 13 to Sep 28 — about 2.6 months when the water holds above 68°F.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 59 | 59 | 59 | 60 | 63 | 65 | 68 | 69 | 69 | 67 | 64 | 60 |
| Comfort | Cool | Cool | Cool | Cool | Cool | Cool | Refreshing | Refreshing | Refreshing | Cool | Cool | Cool |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 59 | Cool |
| Feb | 59 | Cool |
| Mar | 59 | Cool |
| Apr | 60 | Cool |
| May | 63 | Cool |
| Jun | 65 | Cool |
| Jul | 68 | Refreshing |
| Aug | 69 | Refreshing |
| Sep | 69 | Refreshing |
| Oct | 67 | Cool |
| Nov | 64 | Cool |
| Dec | 60 | Cool |
UV index in Costa Mesa in Spring
Clear-sky midday UV across spring averages around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Costa Mesa peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 3 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 3 | 5 | 5 | 7 | 8 | 10 | 10 | 10 | 8 | 6 | 3 | 3 |
| Level | Moderate | Moderate | Moderate | Very high | Very high | Extreme | Extreme | Extreme | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 3 | Moderate |
| Feb | 5 | Moderate |
| Mar | 5 | Moderate |
| Apr | 7 | Very high |
| May | 8 | Very high |
| Jun | 10 | Extreme |
| Jul | 10 | Extreme |
| Aug | 10 | Extreme |
| Sep | 8 | Very high |
| Oct | 6 | High |
| Nov | 3 | Moderate |
| Dec | 3 | Moderate |
Air quality in Costa Mesa in Spring
Average fine-particle pollution (PM2.5) through the year — so you can see where spring falls, not just the annual average.
Air quality in Costa Mesa is worst in September — around 49 µg/m³ PM2.5 (poor), about 4.0× the cleanest month (May, 12 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 18 | 19 | 19 | 17 | 12 | 17 | 19 | 32 | 49 | 21 | 21 | 18 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Poor | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 18 | Moderate |
| Feb | 19 | Moderate |
| Mar | 19 | Moderate |
| Apr | 17 | Moderate |
| May | 12 | Moderate |
| Jun | 17 | Moderate |
| Jul | 19 | Moderate |
| Aug | 32 | Moderate |
| Sep | 49 | Poor |
| Oct | 21 | Moderate |
| Nov | 21 | Moderate |
| Dec | 18 | Moderate |
Where is Costa Mesa?
Costa Mesa sits at 33.6°N, 117.9°W, 98 ft above sea level, in United States. The nearest listed city is Newport Beach, 1.9 mi away.
Topography around Costa Mesa
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Costa Mesa.
Within 2 miles, the terrain around Costa Mesa has only modest variations in elevation — a maximum elevation change of 125 ft around an average of 72 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,168 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 10,013 ft.
The land around Costa Mesa is covered by artificial surfaces (73%) within 2 miles, artificial surfaces (42%) and water (41%) within 10 miles, and water (42%) and artificial surfaces (25%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Costa Mesa (33.6411°, -117.9187°, elevation 98 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.