• Today

    Apr 21

    70°Lo 50°

    Mostly cloudy

    Low ragweed pollen levels
    • Grass
      Pollen
      0 - Low
    • Ragweed
      Pollen
      0 - Low
    • Tree
      Pollen
      350 - High
  • Wed

    Apr 22

    72°Lo 47°

    Low clouds break for some sun

    Low ragweed pollen levels
    • Grass
      Pollen
      0 - Low
    • Ragweed
      Pollen
      0 - Low
    • Tree
      Pollen
      350 - High
    more
  • Thu

    Apr 23

    70°Lo 49°

    Partly sunny

    Low ragweed pollen levels
    • Grass
      Pollen
      0 - Low
    • Ragweed
      Pollen
      0 - Low
    • Tree
      Pollen
      350 - High
    more
  • Fri

    Apr 24

    63°Lo 42°

    Partly sunny and cool

    Low ragweed pollen levels
    • Precip
      25%
    • Wind
      Speed
      12 mph
    • Cloud
      Cover
      44%
    more
  • Sat

    Apr 25

    68°Lo 50°

    Partly sunny and nice

    Ragweed Pollen Weather
    • Precip
      2%
    • Wind
      Speed
      9 mph
    • Cloud
      Cover
      26%
    more
Next Previous
< Previous 8 hours Next 8 hours >
  Tue
4am
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  4am 5am 6am 7am 8am 9am 10am 11am
Forecast
Cloudy
Cloudy
Cloudy
Cloudy
Cloudy
Cloudy
Cloudy
Mostly Cloudy
Temp (°F) 51° 52° 52° 52° 58° 61° 63° 66°
RealFeel® 49° 50° 50° 50° 57° 61° 64° 67°
Humidity 90% 90% 90% 92% 73% 67% 62% 59%
   
  4am 5am 6am 7am 8am 9am 10am 11am
Rain
 
0%
 
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0%
Snow
 
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Ice
 
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  4am 5am 6am 7am 8am 9am 10am 11am
Wind (mph) 6 WNW 6 W 6 W 6 WSW 6 W 6 W 7 W 8 WNW
UV Index 0 0 0 0 0 1 2 2
Cloud Cover 99% 99% 97% 95% 99% 96% 92% 89%
Dew Point 48° 49° 49° 50° 49° 50° 50° 51°
Middle Grid line 70 F Middle Grid line 65 F Middle Grid line 60 F Middle Grid line 55 F Middle Grid line 50 F

Temperature History - Apr 21

more Historical Weather Data >
  Today Normal Record 4/21/2014
High 70° 70° N/A 71°
Low 50° 45° N/A 51°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:26 AM with 13:23 of sunlight, then sets at 7:49 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 8:50 AM with 14:24 of moolight, then sets at 11:14 PM

Los Altos Weather Report

San Francisco: Clouds, Showers to Linger Ahead of Weekend

April 21, 2015; 6:20 AM ET

While cloudy conditions can be expected over the San Francisco area for the next several days, showers will not make a return until the middle of the week. more >

Tue. Pollen

Tue. Dust & Dander

Tue. Wind Maps