Suisun in Spring
In spring (March, April and May), Suisun sees average daytime highs around 71°F and overnight lows near 50°F, with 5.2 in of rain over about 16 wet days across the season. It is the 3rd-warmest season and the 2nd-wettest season.
Over the season highs climb from about 63°F in early March to 79°F by late May. The sky is clear or mostly clear about 46% of the time across spring, and the air most often feels dry.
Spring is Suisun's 2nd-best season to visit on our travel score. For the whole year in context, see Suisun's year-round climate.
- Avg daytime high
- 71°F
- 3rd-warmest season
- Avg overnight low
- 50°F
- Rainfall
- 5.2 in
- 16 wet days
- Avg wind
- 6 mph
- Travel score
- 7.4
- 2nd-best season
- Months
- Mar · Apr · May
Temperature in Suisun in Spring
Over the season highs climb from about 63°F in early March to 79°F by late May.
A typical spring day in Suisun reaches about 71°F and drops to 50°F overnight. The warmest of the three months is May, the coolest March.
Suisun 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 | 58° / 42° | 4.3 | 9.2 | 9.6 | 4.3 |
| Feb | 62° / 44° | 4.2 | 9 | 10.5 | 5.2 |
| Mar | 66° / 46° | 3.1 | 8.2 | 11.7 | 6.4 |
| Apr | 71° / 49° | 1.3 | 4.8 | 13 | 7.5 |
| May | 77° / 53° | 0.7 | 3.2 | 14 | 8.4 |
| Jun | 83° / 57° | 0.2 | 0.9 | 14.6 | 7.7 |
| Jul | 85° / 58° | 0.0 | 0.1 | 14.4 | 7.1 |
| Aug | 85° / 58° | 0.0 | 0.2 | 13.5 | 7.1 |
| Sep | 84° / 57° | 0.1 | 0.4 | 12.3 | 7.7 |
| Oct | 77° / 53° | 0.9 | 2.7 | 11 | 8.5 |
| Nov | 65° / 47° | 2.0 | 5.8 | 9.9 | 6.6 |
| Dec | 58° / 42° | 3.9 | 9 | 9.4 | 4.3 |
Cloud cover in Spring
The sky is clear or mostly clear about 46% of the time across spring.
Chance of precipitation in Spring
Suisun gets around 5.2 in of rain over 16 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 06 min in early March to 14 h 24 min 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 6.0 kWh/m².
Hazard calendar for Suisun
In spring, Suisun overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Suisun's rainy season runs November–March, when most of the year's rain falls.
Is spring a good time to visit Suisun?
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 Suisun for general sightseeing.
What to pack for Suisun in Spring
From spring's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In spring, Suisun sees daytime highs around 71°F and nights near 50°F. Pack sun protection. Worth having: light clothes and rain gear. About 16 days see rain.
Sea temperature near Suisun in Spring
The nearest coast averages about 53°F across spring — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 40 mi away) is warmest in September at about 58°F and coldest in April near 53°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 53 | 53 | 54 | 53 | 53 | 54 | 56 | 58 | 58 | 57 | 55 | 54 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 53 | Bracing |
| Feb | 53 | Bracing |
| Mar | 54 | Bracing |
| Apr | 53 | Bracing |
| May | 53 | Bracing |
| Jun | 54 | Bracing |
| Jul | 56 | Bracing |
| Aug | 58 | Bracing |
| Sep | 58 | Bracing |
| Oct | 57 | Bracing |
| Nov | 55 | Bracing |
| Dec | 54 | Bracing |
UV index in Suisun in Spring
Clear-sky midday UV across spring averages around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Suisun peaks around June 23 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 5 | 6 | 8 | 10 | 10 | 9 | 6 | 5 | 2 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 8 | Very high |
| Jun | 10 | Very high |
| Jul | 10 | Very high |
| Aug | 9 | Very high |
| Sep | 6 | High |
| Oct | 5 | Moderate |
| Nov | 2 | Moderate |
| Dec | 2 | Low |
Air quality in Suisun 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 Suisun is worst in September — around 29 µg/m³ PM2.5 (moderate), about 4.2× the cleanest month (June, 7 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) | 13 | 13 | 13 | 10 | 8 | 7 | 10 | 25 | 29 | 27 | 16 | 12 |
| Level | Moderate | Moderate | Moderate | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 13 | Moderate |
| Feb | 13 | Moderate |
| Mar | 13 | Moderate |
| Apr | 10 | Good |
| May | 8 | Good |
| Jun | 7 | Good |
| Jul | 10 | Good |
| Aug | 25 | Moderate |
| Sep | 29 | Moderate |
| Oct | 27 | Moderate |
| Nov | 16 | Moderate |
| Dec | 12 | Good |
Where is Suisun?
Suisun sits at 38.2°N, 122.0°W, 7 ft above sea level, in United States. The nearest listed city is Fairfield, 0.6 mi away.
Topography around Suisun
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Suisun.
Within 2 miles, the terrain around Suisun has only modest variations in elevation — a maximum elevation change of 194 ft around an average of 16 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,382 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,459 ft.
The land around Suisun is covered by artificial surfaces (40%) and wetland (23%) within 2 miles, grassland (43%) within 10 miles, and grassland (32%) and trees (24%) 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 Suisun (38.2383°, -122.0402°, elevation 7 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.