Castro Valley, California Weather Forecast
Today in Castro Valley: clear skies with a high near 86°F and a low around 54°F. Rain chance 0%. Rain chances peak at 28% on Tuesday. Cooling trend: highs fall from 86°F today to 72°F by Sunday.
Forecast updated 1:05 PM PDT, Oct 15
Active Weather Alerts
7-Day Forecast for Castro Valley
Today 10/15
86°/54°
0%
Fri 10/16
90°/58°
0%
Sat 10/17
87°/62°
0%
Sun 10/18
72°/54°
0%
Mon 10/19
61°/52°
3%
Tue 10/20
63°/51°
28%
Wed 10/21
65°/52°
20%
Next 24 Hours
| Now | 2 PM | 3 PM | 4 PM | 5 PM | 6 PM | 7 PM | 8 PM | 9 PM | 10 PM | 11 PM | Fri12 AM | 1 AM | 2 AM | 3 AM | 4 AM | 5 AM | 6 AM | 7 AM | 8 AM | 9 AM | 10 AM | 11 AM | 12 PM | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sky | | | | | | | |  | | | | | | | | | | | | | | | | |
| Temp | 78° | 81° | 84° | 85° | 86° | 82° | 77° | 72° | 70° | 68° | 66° | 66° | 65° | 63° | 62° | 61° | 60° | 59° | 58° | 59° | 65° | 71° | 76° | 80° |
| Rain | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% |
| Wind | NE 6 | NNE 7 | N 6 | N 5 | N 4 | W 0 | NW 0 | NNW 0 | N 0 | ENE 0 | ENE 0 | ENE 0 | NE 0 | NE 1 | NE 2 | NE 3 | NE 3 | NE 4 | ENE 4 | ENE 5 | ENE 5 | ENE 5 | ENE 6 | ENE 6 |
Growing Conditions
Growing degree days
2,687
since Apr 1, base 50°F
Rain, last 30 days
0.00 in
model analysis
Rain, year to date
15.35 in
since Jan 1
2-inch soil temperature
60°F
yesterday, daily average
Reference ET, last 7 days
0.86 in
FAO-56 grass reference
Through Oct 14. Season totals use model analysis for this point and update every morning.
Soil, ET and spray tools for Castro Valley →
Current Stats & Observations
NWS Forecast
About Castro Valley Weather
Castro Valley sits at about 331 feet above sea level in Alameda County, California. About 63,013 people live in the Castro Valley area. Official forecasts and warnings for the area come from the National Weather Service MTR office, and the nearest NEXRAD radar site is KMUX. The city is in USDA plant hardiness zone 9b, where the coldest winter night typically falls between 25 to 30°F.
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