Diablo, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Diablo, a community in Contra Costa County, California.
Overnight
58°F
Clear
Clear, with a low around 58. South southeast wind around 5 mph.
7-day forecast for Diablo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 58°F | Clear | 5 mph SSE | 0% |
| Tuesday | 101°F | Sunny | 3 to 7 mph SSW | 0% |
| Tuesday Night | 58°F | Clear | 5 mph SSW | 0% |
| Wednesday | 97°F | Sunny | 3 to 7 mph SW | 0% |
| Wednesday Night | 58°F | Mostly Clear | 6 mph WSW | 0% |
| Thursday | 95°F | Sunny | 3 to 7 mph WSW | 0% |
| Thursday Night | 60°F | Mostly Clear | 6 mph WSW | 0% |
| Friday | 99°F | Sunny | 3 to 7 mph WSW | 0% |
| Friday Night | 61°F | Mostly Clear | 3 to 7 mph WSW | 0% |
| Saturday | 99°F | Sunny | 3 to 7 mph WSW | 0% |
| Saturday Night | 62°F | Mostly Clear | 7 mph SW | 0% |
| Sunday | 93°F | Sunny | 5 to 8 mph SW | 0% |
| Sunday Night | 58°F | Mostly Clear | 8 mph SW | 0% |
| Monday | 87°F | Sunny | 9 mph SW | 0% |
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 Aug 4, 2026.