Hawaii and Guam Concerns; Record Warmth Spreads Eastward; Heavy Snow for Sierra-Nevada; Severe Weather for the Plains

A very active spring pattern with tropical concerns across the Pacific. Heavy rainfall will continue to impact Hawaii this weekend. Meanwhile we continue to monitor a developing typhoon that may affect Guam into early next week. For the Lower 48, heavy snow for mountains of California this weekend, increase threat for severe thunderstorms next week for the Plains and record warmth spreads east. Read More >

Current conditions at

SJSU - Mount Diablo Summit Museum Rooftop (SJS02)

Lat: 37.881699°NLon: 121.914173°WElev: 3904.0ft.

NA

38°F

3°C

Humidity 100%
Wind Speed SSW 14 MPH
Barometer NA
Dewpoint 38°F (3°C)
Visibility NA
Wind Chill30°F (-1°C)
Last update 12 Apr 01:00 AM PDT
Extended Forecast for

4 Miles SSE Clayton CA

  • Overnight

    Overnight: A 40 percent chance of showers.  Mostly cloudy, with a low around 46. Southwest wind around 18 mph, with gusts as high as 33 mph.  New precipitation amounts of less than a tenth of an inch possible.

    Low: 46 °F

    Chance
    Showers

  • Sunday

    Sunday: Showers and possibly a thunderstorm, mainly before 4pm, then a chance of showers and thunderstorms after 4pm.  Steady temperature around 48. Southwest wind 15 to 20 mph, with gusts as high as 38 mph.  Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 48 °F

    Showers

  • Sunday Night

    Sunday Night: A 40 percent chance of showers, mainly before 8pm.  Partly cloudy, with a low around 45. West southwest wind 6 to 14 mph, with gusts as high as 24 mph.  New precipitation amounts of less than a tenth of an inch possible.

    Low: 45 °F

    Chance
    Showers then
    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 57. West northwest wind around 7 mph.

    High: 57 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 48. West southwest wind around 10 mph, with gusts as high as 20 mph.

    Low: 48 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 59.

    High: 59 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 47.

    Low: 47 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 59.

    High: 59 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 50.

    Low: 50 °F

    Partly Cloudy

Detailed Forecast

Overnight
A 40 percent chance of showers. Mostly cloudy, with a low around 46. Southwest wind around 18 mph, with gusts as high as 33 mph. New precipitation amounts of less than a tenth of an inch possible.
Sunday
Showers and possibly a thunderstorm, mainly before 4pm, then a chance of showers and thunderstorms after 4pm. Steady temperature around 48. Southwest wind 15 to 20 mph, with gusts as high as 38 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
Sunday Night
A 40 percent chance of showers, mainly before 8pm. Partly cloudy, with a low around 45. West southwest wind 6 to 14 mph, with gusts as high as 24 mph. New precipitation amounts of less than a tenth of an inch possible.
Monday
Mostly sunny, with a high near 57. West northwest wind around 7 mph.
Monday Night
Mostly clear, with a low around 48. West southwest wind around 10 mph, with gusts as high as 20 mph.
Tuesday
Sunny, with a high near 59.
Tuesday Night
Mostly clear, with a low around 47.
Wednesday
Mostly sunny, with a high near 59.
Wednesday Night
Partly cloudy, with a low around 50.
Thursday
Sunny, with a high near 60.
Thursday Night
Clear, with a low around 48.
Friday
Sunny, with a high near 66.
Friday Night
Mostly clear, with a low around 49.
Saturday
Sunny, with a high near 68.
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SSE Clayton CA
 37.9°N 121.9°W (Elev. 1814 ft)
1:25 am PDT Apr 12, 2026
5am PDT Apr 12, 2026-6pm PDT Apr 18, 2026
 
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