Weather in Vallejo, California
Fog and sun in daily rhythm. Day 58 of spring. Read this microseason across nine climate regions →
- TodayMay 16Foggy—76°55°
- SundayMay 17Overcast—76°51°
- MondayMay 18Mostly Clear—85°58°
- TuesdayMay 19Clear—88°59°
- WednesdayMay 20Overcast—83°58°
- ThursdayMay 21Overcast—79°57°
- FridayMay 22Overcast—75°55°
- PM 2.5
- 6.7 μg/m³
- PM 10
- 10.4 μg/m³
- NO₂
- 1.1 μg/m³
- Ozone
- 83.0 μg/m³
- UV Index
- 4.1 Moderate
Flowers blooming in late autumn, a sure sign of a bad winter coming.
- Moonrise
- 12:24 PM
- Moonset
- 2:32 AM
- In sign
- ♉︎ Taurus
Fog and sun in daily rhythm
Vallejo at a glance
- Today vs. normal: 73°F — typical for the season
- Last frost: April 5 (climatological average for this latitude)
- Microseason: 28 of 72, May 16–20
- Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.
Right now in the garden
Warm-season window is open
As of May 16, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.
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
September brings Vallejo's warmest temperatures (~71°F mean) while January delivers the coldest (~50°F). December sees peak rainfall at 4.5 inches, and July remains completely dry at 0.0 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 50° | 4.5″ | 15 |
| February | 54° | 3.6″ | 12 |
| March | 57° | 3.2″ | 11 |
| April | 60° | 1.4″ | 5 |
| May | 65° | 0.8″ | 3 |
| June | 69° | 0.2″ | 1 |
| July | 71° | 0.0″ | 1 |
| August | 71° | 0.0″ | 1 |
| September | 71° | 0.1″ | 1 |
| October | 66° | 1.0″ | 3 |
| November | 56° | 2.2″ | 7 |
| December | 50° | 4.5″ | 15 |
Regional context
Vallejo belongs to a hot-summer Mediterranean climate region — sharing similar temperature ranges, seasonal patterns, and growing conditions with nearby cities in this climate zone.
Similar climates: Los Angeles, CA, San Francisco, CA, San Diego, CA, Riverside, CA, Sacramento, CA.
Naturalist notes
Oak trees begin dropping their pollen in late April, coating surfaces with yellow dust as the trees complete their spring reproductive cycle.
Anna's hummingbirds start their courtship displays in late February, with males performing dramatic dive displays that produce distinctive whistling sounds.
Frequently asked
- When does it freeze in Vallejo?
- Vallejo's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Vallejo?
- December receives the most rainfall with about 4.5 inches on average; the city gets roughly 21 inches annually.
- What is the warmest month in Vallejo?
- September typically brings the warmest weather, averaging about 71°F.
- What is the coldest month in Vallejo?
- January typically brings the coldest weather, averaging about 50°F.
- When can I start a vegetable garden in Vallejo?
- Cool-season crops (peas, lettuce) can be planted around the last spring frost (mid-April); warm-season crops (tomatoes, peppers) should wait until 1–2 weeks after.
- How many rainy days does Vallejo get?
- Vallejo averages about 75 rainy days per year.
- What hardiness zone is Vallejo?
- Vallejo's USDA hardiness zone depends on its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Vallejo, California experiences a hot-summer Mediterranean climate zone. January temperatures hover near 50°F while July averages 71°F — a 21°F seasonal swing.
Throughout the year, Vallejo receives about 21 inches of precipitation spread over roughly 75 rainy days.
Geographic factors shape the local weather patterns: latitude (38.1°N), proximity to large water bodies, and elevation determine what grows here, when frost occurs, and the daily weather conditions.