• Today

    Sep 18

    68°Lo 45°

    Times of clouds and sun

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

    Sep 19

    80°Lo 46°

    Mostly sunny and warmer

    Low ragweed pollen levels
    • Grass
      Pollen
      2 - Low
    • Ragweed
      Pollen
      5 - Low
    • Tree
      Pollen
      0 - Low
    more
  • Sat

    Sep 20

    84°Lo 48°

    A t-storm around in the p.m.

    Low ragweed pollen levels
    • Grass
      Pollen
      2 - Low
    • Ragweed
      Pollen
      5 - Low
    • Tree
      Pollen
      0 - Low
    more
  • Sun

    Sep 21

    82°Lo 47°

    Sun mixing with clouds; warm

    Low ragweed pollen levels
    • Precip
      1%
    • Wind
      Speed
      2 mph
    • Cloud
      Cover
      23%
    more
  • Mon

    Sep 22

    82°Lo 45°

    Plenty of sun

    Ragweed Pollen Weather
    • Precip
      1%
    • Wind
      Speed
      4 mph
    • Cloud
      Cover
      0%
    more
Next Previous
Hi 68° RealFeel® 68° Precipitation 50%

Day

N

E

S

W

  • SSW 10 mph
  • Gusts: 24 mph

Times of clouds and sun with a shower in spots late this afternoon

  • Max UV Index: 5 (Moderate)
  • Thunderstorms: 29%
  • Precipitation: 0.02 in
  • Rain: 0.02 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0.5 hrs
  • Hours of Rain: 0.5 hrs
Lo 45° RealFeel® 45° Precipitation 7%

Night

N

E

S

W

  • N 2 mph
  • Gusts: 7 mph

Mainly clear

  • Max UV Index: N/A
  • Thunderstorms: 24%
  • Precipitation: 0 in
  • Rain: 0 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0 hrs
  • Hours of Rain: 0 hrs

Portola Pollen Levels - September 18

  • Extreme
  • Very High
  • High
  • Moderate
  • Low
  • Grass

    Pollen

    Low

  • Weed

    Pollen

    Low

  • Tree

    Pollen

    Low

  • Mold

    Pollen

    Low

Temperature History - Sep 18

more Historical Weather Data >
  Today Normal Record 9/18/2013
High 68° 75° 86° (1984) 72°
Low 45° 43° 34° (1978) 49°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:46 AM with 12:20 of sunlight, then sets at 7:06 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 1:43 AM with 14:16 of moolight, then sets at 3:59 PM

Top Story

Portola Weather Report

San Francisco: Sunshine, Seasonable Temperatures to Continue

September 18, 2014; 4:37 PM ET

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

Thu. Pollen

Thu. Dust & Dander

Thu. Wind Maps