Hourly Weather Forecast - Portola Valley, CA

12 AM
44°F
50%
5mph
SSE
50% Chance of Rain
Humidity
100%
Feels like
42°F
Dew Point
44°F
1 AM
45°F
50%
5mph
SSE
50% Chance of Rain
Humidity
100%
Feels like
43°F
Dew Point
45°F
2 AM
45°F
50%
4mph
SE
50% Chance of Rain
Humidity
100%
Feels like
43°F
Dew Point
45°F
3 AM
46°F
50%
4mph
SE
50% Chance of Rain
Humidity
100%
Feels like
44°F
Dew Point
46°F
4 AM
46°F
50%
3mph
SE
50% Chance of Rain
Humidity
100%
Feels like
46°F
Dew Point
46°F
5 AM
46°F
40%
3mph
SE
40% Chance of Rain
Humidity
100%
Feels like
45°F
Dew Point
46°F
6 AM
46°F
40%
4mph
SE
40% Chance of Rain
Humidity
100%
Feels like
44°F
Dew Point
46°F

Rainfall and Snowfall Totals Through Thursday

Pineapple Express Slams Northwestern U.S.

The atmospheric river this week will keep buffeting the Pacific Northwest with heavy rain, snow, and high winds.

Wednesday's Weather Outlook

Today's Weather Outlook

How to Measure Snow via NWS

How To Measure Snow

Weekly Drought Map for December 11, 2025

Hit-or-Miss Precipitation Leads to Mixed Drought Results

A person standing in a snowy forest with their back to the camera. They are bundled up in a white hat and a brown jacket. (Image by StockSnap from Pixabay)

Common Cold Weather Illnesses

A strong cold-air-damming event from March 20, 2018.

Cold Air Damming - Cause And Effects

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