Suisun City, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Suisun City weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Mostly Clear——78°56°—
- MondayJul 6Overcast——77°54°-1°
- TuesdayJul 7Overcast——81°53°+4°
- WednesdayJul 8Clear——87°52°+6°
- ThursdayJul 9Overcast——91°54°+4°
- FridayJul 10Overcast——91°55°0°
- SaturdayJul 11Overcast——92°56°+1°
AQI 28 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 5.3 µg/m³, PM10 at 7.1 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 5.3 µg/m³, PM10 at 7.1 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.75
- Wind
- breezy
- Recent rain
- 0h in last 6h
- Pattern
- background
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:27 PM
- Moonset
- 11:26 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Suisun City at a glance
- Today vs. normal: 4°F below the seasonal normal for this latitude
- Last frost: April 5 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 94585
16-Day Forecast — Suisun City
- Sun78°56°0%
- Mon77°54°0%
- Tue81°53°0%
- Wed87°52°0%
- Thu91°54°0%
- Fri91°55°0%
- Sat92°56°0%
- Sun76°63°1%
- Mon100°64°2%
- Tue101°61°4%
- Wed98°59°1%
- Thu99°59°3%
- Fri103°63°0%
- Sat95°60°3%
- Sun91°60°0%
- Mon91°55°3%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Microseason · July 1–5
Summer heat deepens across the valleys
Inland temperatures exceed 95°F regularly; fire danger reaches moderate to high across most of the region.
Day 186 of 365 · Wedge 37 of 72
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
In Suisun City, July runs warmest near 74°F and December coldest around 48°F, while December is the wettest month (5.4 inches) and July the driest (0.0 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 49° | 4.7″ | 8 |
| February | 52° | 5.0″ | 8 |
| March | 56° | 3.3″ | 7 |
| April | 60° | 1.5″ | 3 |
| May | 65° | 0.7″ | 2 |
| June | 71° | 0.2″ | 0 |
| July | 74° | 0.0″ | 0 |
| August | 74° | 0.0″ | 0 |
| September | 72° | 0.1″ | 0 |
| October | 65° | 1.1″ | 2 |
| November | 55° | 2.5″ | 5 |
| December | 48° | 5.4″ | 8 |
Regional context
Per NOAA NCEI 1991-2020 normals, Suisun City runs from a 49°F January mean to 74°F in July, a 25°F seasonal spread, with near 24.5 inches of precipitation across about 42 wet days.
Precipitation in Suisun City peaks in the cool season: December averages 5.4 inches across 7.7 storm-fed days, while July bottoms out at 0.0 inches over just 0.0 rainy days. That cool-season-wet pattern aligns Suisun City with places like Fairfield, CA, Vacaville, CA and Green Valley, CA.
Hard freezes are rare in Suisun City: the coldest month averages 48°F, so Suisun City's growing window runs most of the year. July is the hottest stretch near 74°F, pushing cool-season crops to the milder shoulder months. Within Suisun City, low or inland lots lose 3-5°F overnight versus Suisun City's coastal ground.
Similar climates: Fairfield, CA, Vacaville, CA, Green Valley, CA, Elmira, CA, Hartley, CA.
Frequently asked
- When does it freeze in Suisun City?
- In Suisun City, expect the last spring frost near mid-April; Suisun City's first autumn frost comes around mid-November.
- What is the rainy season in Suisun City?
- December is the wettest month in Suisun City, about 5.4 inches on average; the year totals roughly 25 inches.
- What is the warmest month in Suisun City?
- The warmest stretch in Suisun City comes in July, around 74°F on average.
- What is the coldest month in Suisun City?
- On average December is the chilliest month in Suisun City, about 48°F.
- When can I start a vegetable garden in Suisun City?
- Frost-hardy sowings begin at mid-April in Suisun City; warm-season starts follow two weeks on.
- How many rainy days does Suisun City get?
- Suisun City averages about 42 days with measurable rain or snow each year.
- What hardiness zone is Suisun City?
- Suisun City's hardiness zone tracks its winter low; with December near 48°F, check the USDA ZIP map for the exact zone.
- What is the 10-day forecast for Suisun City?
- Suisun City's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Suisun City?
- See this week's day-by-day rain chances for Suisun City in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Suisun City?
- Current conditions for Suisun City and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Suisun City forecast updated?
- The Suisun City forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Suisun City?
- Today's sunrise and sunset times for Suisun City are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Suisun City?
- The next few days in Suisun City's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Suisun City's hot-summer Mediterranean climate in California pairs 49°F Januarys with 74°F Julys, 25°F apart across the seasons.
Across the year, Suisun City collects about 25 inches of precipitation over roughly 42 days with measurable rain or snow.
The 25°F gap between Suisun City's summer and winter, at 38.2°N, shapes Suisun City's frost calendar.
ZIP codes in Suisun City
- 94585