Diablo, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Diablo, a community in Contra Costa County, California.
This Afternoon
62°F
Light Rain
Rain before 5pm, then a chance of rain and patchy fog. Mostly cloudy. High near 62, with temperatures falling to around 57 in the afternoon. South wind 1 to 6 mph. Chance of precipitation is 80%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Diablo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 62°F | Light Rain | 1 to 6 mph S | 77% |
| Tonight | 46°F | Chance Light Rain then Mostly Cloudy | 1 to 5 mph ENE | 40% |
| Wednesday | 67°F | Sunny | 5 mph NNW | 1% |
| Wednesday Night | 46°F | Partly Cloudy then Patchy Fog | 2 mph W | 0% |
| Thursday | 72°F | Patchy Fog then Sunny | 1 to 5 mph NNW | 0% |
| Thursday Night | 46°F | Mostly Clear | 2 mph SW | 0% |
| Friday | 74°F | Sunny | 3 mph N | 0% |
| Friday Night | 48°F | Clear | 2 mph NNE | 0% |
| Saturday | 75°F | Sunny | 3 mph NE | 0% |
| Saturday Night | 49°F | Mostly Clear | 2 mph NNW | 0% |
| Sunday | 74°F | Mostly Sunny | 3 mph WNW | 0% |
| Sunday Night | 50°F | Partly Cloudy | 2 mph WNW | 0% |
| Monday | 72°F | Partly Sunny | 3 mph WSW | 1% |
| Monday Night | 49°F | Partly Cloudy | 0 to 3 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Diablo (37.841, -121.956). Updated through the day.
Growing snapshot for Diablo
Last spring frost
Mar 8
First fall frost
Dec 22
Growing season
282 days
Hardiness zone
9b
More local growing data for Diablo: nearby ZIP 94528 weather · frost dates · planting calendar · California frost dates
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Climate data from the nearest NOAA station, Mt Diablo Junction, Ca (3 mi from Diablo). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.