Westminster, California Weather
Coastal fog thickens at dawn. Day 77 of spring. Read this microseason across nine climate regions →
Westminster weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Overcast——74°61°—
- ThursdayJun 4Overcast——74°62°0°
- FridayJun 5Overcast——72°59°-2°
- SaturdayJun 6Overcast——73°64°+1°
- SundayJun 7Clear——72°63°-1°
- MondayJun 8Clear——74°63°+2°
- TuesdayJun 9Clear——75°63°+1°
PM2.5 at 12.8 µg/m³, PM10 at 22.3 µg/m³ — typical background levels with no transport signature. AQI flat over the last 6 hours (within ±3 points).
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 36 now. With UV 0.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 9 by mid-afternoon.
- Present
- AQI 36
- UV peak
- 0.0 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 9
PM × Wind × Precip
PM2.5 at 12.8 µg/m³, PM10 at 22.3 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.57
- Wind
- calm
- 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 6:05 AM
- Moonset
- 4:16 PM
- In sign
- ♑︎ Capricorn
Coastal fog thickens at dawn
Westminster at a glance
- Today vs. normal: 19°F below the seasonal normal for this latitude
- Last frost: March 10 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 4, 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.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | lettuce, peas, spinach, radishes | — |
| April | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | — |
| May | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | — | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | — | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | fall brassicas, garlic (overwinter), carrots | — |
| December | — | — |
A year in weather
August is Westminster's warmest month (around 75°F mean) and December its coldest (about 58°F). Rainfall peaks in February at 3.2 inches and bottoms out in August at 0.0 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 59° | 2.9″ | 5 |
| February | 59° | 3.2″ | 5 |
| March | 62° | 1.7″ | 3 |
| April | 64° | 0.8″ | 2 |
| May | 66° | 0.3″ | 1 |
| June | 70° | 0.1″ | 0 |
| July | 74° | 0.0″ | 0 |
| August | 75° | 0.0″ | 0 |
| September | 74° | 0.1″ | 0 |
| October | 69° | 0.5″ | 1 |
| November | 63° | 0.8″ | 2 |
| December | 58° | 2.2″ | 4 |
Regional context
Westminster belongs to a hot-summer Mediterranean climate region. This grouping shares comparable temperature ranges, seasonal timing, and growing conditions with nearby cities.
Similar climates: Los Angeles, CA, San Francisco, CA, San Diego, CA, Riverside, CA, Sacramento, CA.
Naturalist notes
By late May, fledgling American crows are leaving their nests in suburban trees, their hoarse begging calls a reliable sign that spring is advancing toward summer.
Shortly after the summer solstice, the evening sky stays bright past 8 p.m., with Venus appearing low in the west as dusk deepens.
Frequently asked
- When does it freeze in Westminster?
- Westminster's last spring frost usually arrives around mid-March, with the first fall frost near mid-December.
- What is the rainy season in Westminster?
- February is the wettest month, averaging 3.2 inches of rain; the city receives about 13 inches annually.
- What is the warmest month in Westminster?
- August is typically the warmest month, averaging about 75°F.
- What is the coldest month in Westminster?
- December is typically the coldest month, averaging about 58°F.
- When can I start a vegetable garden in Westminster?
- Cool-season crops such as peas and lettuce can be sown around the last spring frost (mid-March), while warm-season crops like tomatoes and peppers should wait until 1–2 weeks after.
- How many rainy days does Westminster get?
- Westminster averages roughly 22 rainy days per year.
- What hardiness zone is Westminster?
- Westminster's USDA hardiness zone reflects its lowest average winter temperature; refer to the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Westminster, California lies within a hot-summer Mediterranean climate zone. Mean temperatures for January hover near 59°F while July averages 74°F, a 15°F seasonal swing.
The city receives about 13 inches of precipitation across roughly 22 rainy days each year.
Latitude (33.8°N), nearby large water bodies, and elevation set the yearly rhythm. These factors determine what can grow, when frost is likely, and the daily weather story.