Rancho Cucamonga, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Rancho Cucamonga, a city in San Bernardino County, California.
Today
86°F
Sunny
Sunny, with a high near 86. Southwest wind 5 to 10 mph.
7-day forecast for Rancho Cucamonga
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 86°F | Sunny | 5 to 10 mph SW | 0% |
| Tonight | 63°F | Partly Cloudy | 0 to 10 mph W | 0% |
| Sunday | 84°F | Mostly Sunny | 0 to 10 mph SW | 0% |
| Sunday Night | 63°F | Partly Cloudy | 0 to 10 mph SW | 3% |
| Monday | 80°F | Mostly Sunny | 0 to 10 mph SW | 3% |
| Monday Night | 61°F | Partly Cloudy | 0 to 10 mph W | 2% |
| Tuesday | 83°F | Sunny | 0 to 5 mph SW | 0% |
| Tuesday Night | 63°F | Clear | 0 to 5 mph NW | 0% |
| Wednesday | 90°F | Sunny | 0 to 10 mph W | 0% |
| Wednesday Night | 66°F | Mostly Clear | 0 to 10 mph W | 0% |
| Thursday | 91°F | Sunny | 0 to 10 mph W | 3% |
| Thursday Night | 67°F | Mostly Clear | 0 to 10 mph W | 3% |
| Friday | 90°F | Sunny | 0 to 5 mph SW | 4% |
| Friday Night | 67°F | Mostly Clear | 0 to 5 mph W | 1% |
Forecast source: National Weather Service (api.weather.gov) for Rancho Cucamonga (34.130, -117.566). Updated through the day.
Growing snapshot for Rancho Cucamonga
Last spring frost
Jan 4
First fall frost
Dec 30
Growing season
365 days
Hardiness zone
10a
More local growing data for Rancho Cucamonga: nearby ZIP 91737 weather · frost dates · planting calendar · California frost dates
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Climate data from the nearest NOAA station, Ontario Intl Ap, Ca (7 mi from Rancho Cucamonga). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.