Castroville, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Castroville weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Foggy——62°55°—
- MondayJul 6Foggy——62°54°0°
- TuesdayJul 7Overcast——66°53°+4°
- WednesdayJul 8Clear——67°52°+1°
- ThursdayJul 9Mostly Clear——68°54°+1°
- FridayJul 10Overcast——67°53°-1°
- SaturdayJul 11Overcast——70°53°+3°
AQI 32 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 7.5 µg/m³ (AQI 42) with a 0.71 fine-to-coarse ratio and 5 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 7.5 µg/m³ (AQI 42) with a 0.71 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.71
- Wind
- light
- 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
- 11:25 PM
- Moonset
- 11:26 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Castroville at a glance
- Today vs. normal: 15°F below the seasonal normal for this latitude
- Last frost: March 28 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 95012
16-Day Forecast — Castroville
- Sun62°55°0%
- Mon62°54°0%
- Tue66°53°0%
- Wed67°52°0%
- Thu68°54°0%
- Fri67°53°0%
- Sat70°53°0%
- Sun67°58°2%
- Mon85°58°5%
- Tue76°58°5%
- Wed73°56°1%
- Thu75°56°2%
- Fri74°57°0%
- Sat69°56°0%
- Sun70°55°3%
- Mon70°53°3%
Forecast data from Open-Meteo (CC BY 4.0).
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
The year in Castroville tops out in September (~64°F) and dips lowest in December (~51°F), with January wettest at 2.6 inches and July driest at 0.0 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 52° | 2.6″ | 6 |
| February | 53° | 2.4″ | 6 |
| March | 55° | 2.1″ | 5 |
| April | 57° | 0.9″ | 3 |
| May | 59° | 0.4″ | 1 |
| June | 62° | 0.1″ | 0 |
| July | 63° | 0.0″ | 0 |
| August | 64° | 0.0″ | 0 |
| September | 64° | 0.1″ | 0 |
| October | 62° | 0.6″ | 1 |
| November | 56° | 1.3″ | 3 |
| December | 51° | 2.1″ | 5 |
Regional context
Castroville swings from 52°F in January to 63°F in July (11°F) per NOAA NCEI 1991-2020 normals; precipitation in Castroville runs about 12.6 inches on roughly 31 measurable days.
Castroville's moisture rides winter storm tracks: January brings 2.6 inches over 6.0 wet days, while July sees only 0.0 inches across 0.0 days in the dry warm season. It is a winter-storm rhythm Castroville shares with places like Moss Landing, CA, Elkhorn, CA and Marina, CA.
Hard freezes are rare in Castroville: the coldest month averages 51°F, so Castroville's growing window runs most of the year. September is the hottest stretch near 64°F, pushing cool-season crops to the milder shoulder months. Within Castroville, low or inland lots lose 3-5°F overnight versus Castroville's coastal ground.
Similar climates: Moss Landing, CA, Elkhorn, CA, Marina, CA, Prunedale, CA, Boronda, CA.
Frequently asked
- When does it freeze in Castroville?
- Frost typically leaves Castroville by mid-April and returns to Castroville near mid-November.
- What is the rainy season in Castroville?
- January is the wettest month in Castroville, about 2.6 inches on average; the year totals roughly 13 inches.
- What is the warmest month in Castroville?
- September is Castroville's warmest month, averaging about 64°F.
- What is the coldest month in Castroville?
- Castroville bottoms out in December, with a mean near 51°F.
- When can I start a vegetable garden in Castroville?
- Time tomatoes in Castroville for two weeks after mid-April; peas and greens start at Castroville's frost line.
- How many rainy days does Castroville get?
- Castroville averages about 31 days with measurable rain or snow each year.
- What hardiness zone is Castroville?
- Castroville sits in the USDA zone set by December lows near 51°F; the USDA ZIP tool gives the band.
- What is the 10-day forecast for Castroville?
- Castroville'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 Castroville?
- See this week's day-by-day rain chances for Castroville in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Castroville?
- Current conditions for Castroville and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Castroville forecast updated?
- The Castroville forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Castroville?
- Today's sunrise and sunset times for Castroville 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 Castroville?
- The next few days in Castroville's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Castroville's hot-summer Mediterranean climate in California pairs 52°F Januarys with 63°F Julys, 11°F apart across the seasons.
In a typical year Castroville records about 13 inches of precipitation on around 31 days.
At 36.8°N, Castroville's 11°F summer-to-winter swing sets when Castroville's gardens wake and when frost returns.
ZIP codes in Castroville
- 95012