Ontario, OR Weather & Growing Conditions
Overnight
54°F
Mostly Cloudy
Mostly cloudy. Low around 54, with temperatures rising to around 58 overnight. Northwest wind around 8 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 54°F | Mostly Cloudy | 8 mph NW | 8% |
| Saturday | 80°F | Mostly Sunny | 5 to 9 mph N | 8% |
| Saturday Night | 52°F | Mostly Clear | 2 to 7 mph N | 2% |
| Sunday | 81°F | Sunny | 5 mph ENE | 0% |
| Sunday Night | 51°F | Mostly Clear | 0 to 6 mph NE | 0% |
| Monday | 82°F | Sunny | 2 to 6 mph E | 0% |
| Monday Night | 54°F | Partly Cloudy | 1 to 9 mph NNW | 0% |
| Tuesday | 84°F | Sunny | 2 to 7 mph NNE | 0% |
| Tuesday Night | 54°F | Mostly Clear | 3 mph NE | 0% |
| Wednesday | 84°F | Sunny | 5 mph NNE | 0% |
| Wednesday Night | 53°F | Partly Cloudy | 5 mph NNE | 0% |
| Thursday | 84°F | Sunny | 6 mph N | 0% |
| Thursday Night | 54°F | Partly Cloudy | 5 mph N | 2% |
| Friday | 81°F | Mostly Sunny | 6 mph WNW | 0% |
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 Sep 19, 2026.