Vacaville, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Vacaville weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Mostly Clear——82°65°—
- MondayJul 6Overcast——83°61°+1°
- TuesdayJul 7Partly Cloudy——88°51°+5°
- WednesdayJul 8Clear——97°52°+9°
- ThursdayJul 9Clear——94°56°-3°
- FridayJul 10Overcast——99°55°+5°
- SaturdayJul 11Overcast——101°59°+2°
AQI 29 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 5.2 µg/m³, PM10 at 6.9 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 5.2 µg/m³, PM10 at 6.9 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
Vacaville at a glance
- Today vs. normal: 75°F — typical for the season
- Last frost: April 6 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP codes: 95687, 95688
16-Day Forecast — Vacaville
- Sun83°65°0%
- Mon83°61°0%
- Tue88°51°0%
- Wed97°52°0%
- Thu94°56°0%
- Fri99°55°0%
- Sat101°59°0%
- Sun104°58°1%
- Mon109°72°2%
- Tue104°68°3%
- Wed91°64°1%
- Thu95°72°3%
- Fri110°73°3%
- Sat113°75°3%
- Sun108°65°0%
- Mon100°57°3%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Vacaville
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
Vacaville peaks at about 74°F in July and bottoms near 48°F in December; December brings the heaviest rain (5.4 inches) and July the least (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
By the nearest station's NOAA NCEI 1991-2020 normals, Vacaville sees 49°F Januarys and 74°F Julys, a 25°F range, plus around 24.5 inches of precipitation across 42 days.
Vacaville's moisture rides winter storm tracks: December brings 5.4 inches over 7.7 wet days, while July sees only 0.0 inches across 0.0 days in the dry warm season. It is a winter-storm rhythm Vacaville shares with places like Elmira, CA, Hartley, CA and Allendale, CA.
Vacaville rarely sees a hard freeze — its coldest month sits near 48°F — so planting spans most of the calendar. Heat peaks in July around 74°F, which confines cool-season crops to the shoulders of summer. Within Vacaville, low or inland lots lose 3-5°F overnight versus Vacaville's coastal ground.
Similar climates: Elmira, CA, Hartley, CA, Allendale, CA, Fairfield, CA, Suisun City, CA.
Naturalist notes
Western kingbirds return to the lower Sacramento Valley by mid-April, a reliable phenological marker as last frost exits the Vacaville area.
In late spring, the first brood of pipevine swallowtail butterflies appears on California Dutchman's pipe, coinciding with soil temperatures warm enough for warm-season vegetable starts.
Frequently asked
- When does it freeze in Vacaville?
- Vacaville's last spring frost lands near mid-April, and in Vacaville the first fall frost follows around mid-November.
- What is the rainy season in Vacaville?
- Rainfall in Vacaville peaks in December near 5.4 inches, out of about 25 inches annually.
- What is the warmest month in Vacaville?
- Vacaville peaks in July, when the mean runs near 74°F.
- What is the coldest month in Vacaville?
- December is Vacaville's coldest month, averaging about 48°F.
- When can I start a vegetable garden in Vacaville?
- Hardy spring crops go in near mid-April in Vacaville; tender peppers and squash wait 10–14 days.
- How many rainy days does Vacaville get?
- Expect roughly 42 wet days a year in Vacaville.
- What hardiness zone is Vacaville?
- With December around 48°F, Vacaville's zone reflects that minimum — the USDA ZIP map confirms Vacaville's band.
- What is the 10-day forecast for Vacaville?
- Vacaville'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 Vacaville?
- See this week's day-by-day rain chances for Vacaville in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Vacaville?
- Current conditions for Vacaville and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Vacaville forecast updated?
- The Vacaville forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Vacaville?
- Today's sunrise and sunset times for Vacaville 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 Vacaville?
- The next few days in Vacaville's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Set in a hot-summer Mediterranean zone, Vacaville, California swings from 49°F in the heart of winter to 74°F at midsummer — a 25°F arc.
Across the year, Vacaville collects about 25 inches of precipitation over roughly 42 days with measurable rain or snow.
Vacaville's 25°F range, set by its 38.4°N position, drives frost timing and what thrives in Vacaville.
ZIP codes in Vacaville
- 95687
- 95688