Brentwood, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Brentwood weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Partly Cloudy——87°60°—
- MondayJul 6Overcast——86°54°-1°
- TuesdayJul 7Partly Cloudy——89°53°+3°
- WednesdayJul 8Clear——97°52°+8°
- ThursdayJul 9Clear——99°57°+2°
- FridayJul 10Overcast——103°58°+4°
- SaturdayJul 11Overcast——104°64°+1°
AQI 33 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 7.3 µg/m³ (AQI 41) with a 0.74 fine-to-coarse ratio and 2 mph wind — combustion smoke trapped in calm air, not road dust.
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 7.3 µg/m³ (AQI 41) with a 0.74 fine-to-coarse ratio and 2 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.74
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
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
- 11:26 PM
- Moonset
- 11:25 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Brentwood at a glance
- Today vs. normal: 3°F above the seasonal normal for this latitude
- Last frost: April 4 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 94513
16-Day Forecast — Brentwood
- Sun87°60°0%
- Mon86°54°0%
- Tue89°53°0%
- Wed97°52°0%
- Thu99°57°0%
- Fri103°58°0%
- Sat104°64°0%
- Sun86°68°1%
- Mon100°68°2%
- Tue106°66°4%
- Wed106°65°1%
- Thu108°64°3%
- Fri110°72°3%
- Sat105°68°3%
- Sun101°63°3%
- Mon102°59°6%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Brentwood
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
July is Brentwood's warmest stretch (~76°F) and January its coldest (~48°F); precipitation crests in January at 2.7 inches and ebbs in July to 0.0 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 48° | 2.7″ | 6 |
| February | 52° | 2.4″ | 6 |
| March | 57° | 1.9″ | 5 |
| April | 61° | 0.9″ | 2 |
| May | 67° | 0.4″ | 1 |
| June | 73° | 0.1″ | 0 |
| July | 76° | 0.0″ | 0 |
| August | 75° | 0.0″ | 0 |
| September | 73° | 0.1″ | 0 |
| October | 66° | 0.4″ | 1 |
| November | 55° | 1.2″ | 3 |
| December | 48° | 2.5″ | 6 |
Regional context
Brentwood swings from 48°F in January to 76°F in July (28°F) per NOAA NCEI 1991-2020 normals; precipitation in Brentwood runs about 12.6 inches on roughly 30 measurable days.
Cool-season fronts carry Brentwood's rain: January logs 2.7 inches on 6.4 days, against July's 0.0 inches on 0.0 — winter does the heavy lifting in Brentwood. That groups Brentwood with places like Knightsen, CA, Oakley, CA and Antioch, CA on the same cool-season storm track.
Hard freezes are rare in Brentwood: the coldest month averages 48°F, so Brentwood's growing window runs most of the year. July is the hottest stretch near 76°F, pushing cool-season crops to the milder shoulder months. Brentwood's coastal lots stay 4-7°F milder overnight than Brentwood's inland parcels.
Similar climates: Knightsen, CA, Oakley, CA, Antioch, CA, Byron, CA, Discovery Bay, CA.
Frequently asked
- When does it freeze in Brentwood?
- In Brentwood, expect the last spring frost near mid-April; Brentwood's first autumn frost comes around mid-November.
- What is the rainy season in Brentwood?
- Brentwood sees its heaviest rain in January (around 2.7 inches), part of roughly 13 inches a year.
- What is the warmest month in Brentwood?
- July is Brentwood's warmest month, averaging about 76°F.
- What is the coldest month in Brentwood?
- Brentwood bottoms out in January, with a mean near 48°F.
- When can I start a vegetable garden in Brentwood?
- Time tomatoes in Brentwood for two weeks after mid-April; peas and greens start at Brentwood's frost line.
- How many rainy days does Brentwood get?
- Expect roughly 30 wet days a year in Brentwood.
- What hardiness zone is Brentwood?
- Brentwood sits in the USDA zone set by January lows near 48°F; the USDA ZIP tool gives the band.
- What is the 10-day forecast for Brentwood?
- Brentwood'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 Brentwood?
- See this week's day-by-day rain chances for Brentwood in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Brentwood?
- Current conditions for Brentwood and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Brentwood forecast updated?
- The Brentwood forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Brentwood?
- Today's sunrise and sunset times for Brentwood 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 Brentwood?
- The next few days in Brentwood's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Brentwood, California occupies a hot-summer Mediterranean zone, with January means near 48°F and July around 76°F — a 28°F swing.
Yearly precipitation in Brentwood totals around 13 inches, spread over about 30 days of rain or snow.
The 28°F gap between Brentwood's summer and winter, at 37.9°N, shapes Brentwood's frost calendar.
ZIP codes in Brentwood
- 94513