• Today

    Sep 16

    78°Lo 60°

    Mostly sunny

    Low ragweed pollen levels
    • Grass
      Pollen
      0 - Low
    • Ragweed
      Pollen
      5 - Low
    • Tree
      Pollen
      7 - Low
    more
  • Wed

    Sep 17

    76°Lo 65°

    Sunny to partly cloudy

    Low ragweed pollen levels
    • Grass
      Pollen
      0 - Low
    • Ragweed
      Pollen
      5 - Low
    • Tree
      Pollen
      7 - Low
  • Thu

    Sep 18

    77°Lo 62°

    Partly sunny

    Low ragweed pollen levels
    • Grass
      Pollen
      0 - Low
    • Ragweed
      Pollen
      5 - Low
    • Tree
      Pollen
      7 - Low
    more
  • Fri

    Sep 19

    78°Lo 61°

    Mostly sunny and pleasant

    Low ragweed pollen levels
    • Precip
      0%
    • Wind
      Speed
      7 mph
    • Cloud
      Cover
      19%
    more
  • Sat

    Sep 20

    81°Lo 61°

    Plenty of sunshine

    Ragweed Pollen Weather
    • Precip
      1%
    • Wind
      Speed
      6 mph
    • Cloud
      Cover
      10%
    more
Next Previous
< Previous 8 hours Next 8 hours >
  Wed
6am
7am 8am 9am 10am 11am 12pm 1pm
  6am 7am 8am 9am 10am 11am 12pm 1pm
Forecast
Mostly Clear
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Temp (°F) 60° 60° 61° 62° 64° 67° 70° 73°
RealFeel® 57° 57° 59° 62° 66° 70° 73° 75°
Humidity 86% 86% 84% 80% 74% 67% 62% 55%
   
  6am 7am 8am 9am 10am 11am 12pm 1pm
Rain
 
0%
 
0%
 
1%
 
1%
 
1%
 
1%
 
1%
 
2%
Snow
 
0%
 
0%
 
0%
 
0%
 
0%
 
0%
 
0%
 
0%
Ice
 
0%
 
0%
 
0%
 
0%
 
0%
 
0%
 
0%
 
0%
   
  6am 7am 8am 9am 10am 11am 12pm 1pm
Wind (mph) 5 WSW 5 WSW 5 SW 6 WSW 6 WSW 7 WSW 8 WSW 9 WSW
UV Index 0 0 0 1 3 4 6 6
Cloud Cover 25% 25% 25% 25% 25% 25% 25% 25%
Dew Point 56° 56° 56° 56° 56° 56° 57° 56°
Middle Grid line 75 F Middle Grid line 70 F Middle Grid line 65 F Middle Grid line 60 F Middle Grid line 55 F

Temperature History - Sep 17

more Historical Weather Data >
  Today Normal Record 9/17/2013
High 76° N/A N/A 71°
Low 65° N/A N/A 58°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:52 AM with 12:21 of sunlight, then sets at 7:13 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 1:01 AM with 14:21 of moolight, then sets at 3:22 PM

Top Story

Castro Valley Weather Report

San Francisco: Sunshine, Seasonable Temperatures to Continue

September 16, 2014; 7:27 AM ET

The Bay Area will continue to feature sunshine and seasonable temperatures as the summer season comes to a close. more >

Wed. Pollen

Wed. Dust & Dander

Wed. Wind Maps