Ontario, OR Weather & Growing Conditions
Overnight
37°F
Mostly Cloudy
Mostly cloudy. Low around 37, with temperatures rising to around 41 overnight. Northwest wind around 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 37°F | Mostly Cloudy | 10 mph NW | 2% |
| Wednesday | 59°F | Sunny | 5 to 9 mph W | 1% |
| Wednesday Night | 38°F | Mostly Cloudy | 5 mph NW | 4% |
| Thursday | 56°F | Mostly Sunny | 3 to 7 mph NNW | 4% |
| Thursday Night | 32°F | Mostly Clear | 6 mph N | 0% |
| Friday | 52°F | Mostly Sunny | 3 mph NE | 0% |
| Friday Night | 30°F | Partly Cloudy | 5 mph NNW | 0% |
| Saturday | 56°F | Mostly Sunny | 1 to 5 mph NE | 0% |
| Saturday Night | 35°F | Partly Cloudy | 3 mph NE | 0% |
| Sunday | 58°F | Mostly Sunny | 3 mph NE | 0% |
| Sunday Night | 35°F | Mostly Cloudy | 3 mph NNW | 0% |
| Monday | 57°F | Partly Sunny | 2 mph NNE | 0% |
| Monday Night | 35°F | Mostly Cloudy | 1 mph NW | 6% |
| Tuesday | 59°F | Mostly Sunny | 1 mph NNE | 8% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Ontario, OR
Last spring frost
Apr 21
First fall frost
Oct 14
Growing season
176 days
Hardiness zone
7a
Explore more for Ontario, OR: full frost dates · planting calendar · Oregon frost dates
Climate data from the nearest NOAA station, Ontario Muni Ap, Or (7.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.