Ontario, CA Weather & Growing Conditions
Today
93°F
Sunny
Sunny, with a high near 93. West wind 5 to 15 mph, with gusts as high as 25 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 93°F | Sunny | 5 to 15 mph W | 0% |
| Tonight | 67°F | Mostly Clear | 0 to 10 mph W | 0% |
| Wednesday | 94°F | Sunny | 0 to 15 mph W | 0% |
| Wednesday Night | 68°F | Mostly Clear | 0 to 10 mph W | 0% |
| Thursday | 96°F | Sunny | 0 to 10 mph SW | 1% |
| Thursday Night | 69°F | Mostly Clear | 0 to 10 mph W | 1% |
| Friday | 95°F | Sunny | 0 to 10 mph SW | 0% |
| Friday Night | 69°F | Mostly Clear | 0 to 10 mph W | 0% |
| Saturday | 97°F | Sunny | 0 to 10 mph SW | 0% |
| Saturday Night | 69°F | Mostly Clear | 0 to 10 mph SW | 0% |
| Sunday | 96°F | Sunny | 0 to 10 mph SW | 0% |
| Sunday Night | 68°F | Mostly Clear | 0 to 10 mph SW | 1% |
| Monday | 93°F | Sunny | 0 to 10 mph SW | 2% |
| Monday Night | 66°F | Mostly Clear | 0 to 10 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Ontario, CA
Last spring frost
Jan 4
First fall frost
Dec 30
Growing season
365 days
Hardiness zone
10a
Explore more for Ontario, CA: full frost dates · planting calendar · California frost dates
Climate data from the nearest NOAA station, Ontario Intl Ap, Ca (4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.