Thermal, California Weather
Coastal fog thickens at dawn. Day 76 of spring. Read this microseason across nine climate regions →
Thermal weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Overcast——107°75°—
- ThursdayJun 4Clear——108°74°+1°
- FridayJun 5Clear——109°74°+1°
- SaturdayJun 6Overcast——103°74°-6°
- SundayJun 7Overcast——100°73°-3°
- MondayJun 8Overcast——100°73°0°
- TuesdayJun 9Overcast——102°71°+2°
Ozone at AQI 93. AQI up 8 over the last 6 hours (gradual rise). Overcast through the UV peak window (cloud cover ~67%) — afternoon ozone should stay flat.
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 93. Overcast through the UV peak window (cloud cover ~67%) — afternoon ozone should stay flat.
- Present
- AQI 93
- UV peak
- 10.0 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 62
PM × Wind × Precip
PM10 at 15.2 µg/m³ (AQI 14) with a 0.32 fine-to-coarse ratio under 10 mph wind — coarse road or agricultural dust being kicked up.
- PM2.5/PM10
- 0.32
- Wind
- breezy
- Recent rain
- 0h in last 6h
- Pattern
- blown dust
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).
The higher the clouds, the finer the weather.
- Moonrise
- 5:17 AM
- Moonset
- 3:08 PM
- In sign
- ♑︎ Capricorn
Coastal fog thickens at dawn
Thermal at a glance
- Today vs. normal: 23°F above the seasonal normal for this latitude
- Last frost: March 9 (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 3, 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
Thermal's warmest month is July (~94°F mean) and its coldest is December (~57°F). Rainfall peaks in January (0.7 inches) and bottoms out in June (0.0 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 59° | 0.7″ | 2 |
| February | 62° | 0.6″ | 1 |
| March | 69° | 0.3″ | 1 |
| April | 75° | 0.1″ | 0 |
| May | 81° | 0.0″ | 0 |
| June | 89° | 0.0″ | 0 |
| July | 94° | 0.1″ | 0 |
| August | 94° | 0.3″ | 0 |
| September | 89° | 0.1″ | 0 |
| October | 78° | 0.1″ | 0 |
| November | 66° | 0.2″ | 0 |
| December | 57° | 0.5″ | 1 |
Frequently asked
- When does it freeze in Thermal?
- Thermal's last spring frost typically falls around mid-March, and the first fall frost arrives around mid-December.
- What is the rainy season in Thermal?
- January is the wettest month with about 0.7 inches of rain on average; the city receives roughly 3 inches annually.
- What is the warmest month in Thermal?
- July is typically warmest, averaging about 94°F.
- What is the coldest month in Thermal?
- December is typically coldest, averaging about 57°F.
- When can I start a vegetable garden in Thermal?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-March); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Thermal get?
- Thermal averages about 6 rainy days per year.
- What hardiness zone is Thermal?
- Thermal's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Thermal, California sits in a hot-summer Mediterranean climate zone. January means hover near 59°F while July averages 94°F — a 35°F seasonal swing.
Across the year, Thermal receives about 3 inches of precipitation spread over roughly 6 rainy days.
The rhythm of the year is set by latitude (33.6°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.