
Critical Fire Weather in the Southern High Plains; Heavy Snow in the Great Lakes and Northeast U.S.
Gusty winds and low relative humidity will bring critical fire weather to the southern High Plains Friday. A winter storm will track across the Great Lakes and Northeast U.S. Friday into Saturday with areas of wintry mix and heavy snow from northern New York through southern Maine. Read More >
Hazardous Weather Conditions
Current conditions at
SJSU - Mount Diablo Summit Museum Rooftop (SJS02)
Lat: 37.881699°NLon: 121.914173°WElev: 3904.0ft.NA
29°F
-2°C
| Humidity | 99% |
| Wind Speed | N 0 MPH |
| Barometer | NA |
| Dewpoint | 28°F (-2°C) |
| Visibility | NA |
| Last update | 19 Feb 11:20 PM PST |
Extended Forecast for
3 Miles S Clayton CA
Extreme Cold Warning February 20, 01:00am until February 20, 09:00am
Tonight

Low: 32 °F
Frost
Friday

High: 46 °F
Frost then
Partly SunnyFriday Night

Low: 36 °F
Partly Cloudy
Saturday

High: 53 °F
Mostly Sunny
Saturday Night

Low: 46 °F
Slight Chance
RainSunday

High: 60 °F
Chance Rain
Sunday Night

Low: 50 °F
Chance Rain
Monday

High: 61 °F
Chance Rain
Monday Night

Low: 55 °F
Rain
Detailed Forecast
Tonight
Widespread frost after 2am. Otherwise, mostly clear, with a low around 32. West southwest wind 8 to 11 mph, with gusts as high as 22 mph.
Friday
Widespread frost before 8am. Otherwise, mostly sunny, with a high near 46. South southeast wind around 6 mph becoming north northwest in the afternoon.
Friday Night
Partly cloudy, with a low around 36. Southeast wind 6 to 9 mph.
Saturday
Mostly sunny, with a high near 53. South southeast wind 10 to 14 mph, with gusts as high as 25 mph.
Saturday Night
A 20 percent chance of rain after 10pm. Partly cloudy, with a low around 46. South southeast wind around 16 mph, with gusts as high as 31 mph. New precipitation amounts of less than a tenth of an inch possible.
Sunday
A 40 percent chance of rain. Partly sunny, with a high near 60. New precipitation amounts of less than a tenth of an inch possible.
Sunday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 50.
Monday
A chance of rain. Partly sunny, with a high near 61.
Monday Night
Rain. Mostly cloudy, with a low around 55.
Tuesday
Rain. Mostly cloudy, with a high near 56.
Tuesday Night
Rain. Mostly cloudy, with a low around 52.
Wednesday
Rain likely. Mostly cloudy, with a high near 58.
Wednesday Night
A chance of rain. Mostly cloudy, with a low around 50.
Thursday
A chance of rain. Mostly sunny, with a high near 60.
Additional Forecasts and Information
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ABOUT THIS FORECAST
Point Forecast:
3 Miles S Clayton CA
37.9°N 121.92°W (Elev. 1900 ft)
37.9°N 121.92°W (Elev. 1900 ft)
8:22 pm PST Feb 19, 2026
11pm PST Feb 19, 2026-6pm PST Feb 26, 2026



