Today
Expect clear. Daytime high +86°, overnight low +68°. Light wind, up to 3 mph. No rain expected.
Weather in Castro Valley
United States · California · 37.6941, -122.0864
Today Now 4:48 PM
+86° Clear
Hourly forecast
Today10/16
Temperature°F
Cloudiness
Precipitation
Windmph
Wind gusts
Humidity
PressureinHg
Dew point°F
Visibilitymi
UV index
Forecast in words
Tomorrow
Tomorrow high +88° and clear, nighttime low +64°, no noticeable change.
Week
Seven days ahead fall within +48°…+88°. Weekly maximum — +88° (Sat). Coldest night — Thu, around +48°. Days with precipitation — Tue. Sunshine expected on 5 of seven days. Second half of the week is cooler.
Week vs norm
- Today 10/16 +86° +11° usually +75°
- Tomorrow 10/17 +88° +13° usually +75°
- Sun 10/18 +73° −1° usually +75°
- Mon 10/19 +63° −12° usually +74°
- Tue 10/20 +64° −9° usually +74°
- Wed 10/21 +70° −4° usually +73°
- Thu 10/22 +66° −7° usually +73°
- Fri 10/23 +68° −5° usually +73°
Difference between forecast daytime high and the 1991–2020 norm for this date.
This day, October 16
Today is one of the warmest such days in three decades.
- Heat record +90° 2020
- Cold record +45° 2018
- Most precipitation 0.7 in 2016
- Strongest gust 38 mph 2016
Records for this calendar date, 1991-2024, ERA5 reanalysis.
Climate in Castro Valley
Today is about 11° warmer than usual for October.
| Month | Daytime / Nighttime | Average | Precipitation in |
|---|---|---|---|
| Jan | +58° / +42° | +49° | 3.6 |
| Feb | +60° / +43° | +50° | 3.8 |
| Mar | +63° / +45° | +53° | 3.0 |
| Apr | +67° / +46° | +55° | 1.4 |
| May | +72° / +50° | +59° | 0.7 |
| Jun | +77° / +54° | +64° | 0.2 |
| Jul | +80° / +56° | +66° | 0.0 |
| Aug | +81° / +57° | +67° | 0.1 |
| Sep | +81° / +56° | +66° | 0.1 |
| Oct | +75° / +53° | +62° | 0.9 |
| Nov | +65° / +47° | +55° | 1.8 |
| Dec | +58° / +43° | +49° | 3.6 |
Climatic normals for 1991–2025 years from ERA5-Land reanalysis.
Astronomical data
Sunrise / sunset
7:18 AM | 6:29 PM
Moon
1:18 PM | 10:28 PM
Moon phase
Waxing crescent 33%
Next solar eclipse
Calculating for this city…