Ontario, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Ontario, a village in Vernon County, Wisconsin.
This Afternoon
67°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy. High near 67, with temperatures falling to around 62 in the afternoon. East wind around 9 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Ontario
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 67°F | Showers And Thunderstorms | 9 mph E | 92% |
| Tonight | 54°F | Showers And Thunderstorms | 10 to 15 mph E | 92% |
| Saturday | 70°F | Showers And Thunderstorms | 6 to 12 mph E | 85% |
| Saturday Night | 52°F | Showers And Thunderstorms Likely | 5 to 8 mph NE | 72% |
| Sunday | 69°F | Slight Chance Rain Showers then Partly Sunny | 8 to 13 mph NE | 16% |
| Sunday Night | 47°F | Mostly Cloudy | 9 mph NE | 5% |
| Monday | 64°F | Mostly Cloudy then Chance Rain Showers | 7 to 12 mph NE | 29% |
| Monday Night | 43°F | Chance Rain Showers | 3 to 9 mph NE | 29% |
| Tuesday | 63°F | Slight Chance Rain Showers then Partly Sunny | 3 to 8 mph NE | 23% |
| Tuesday Night | 42°F | Partly Cloudy | 0 to 5 mph NE | 4% |
| Wednesday | 67°F | Mostly Sunny | 0 to 5 mph E | 2% |
| Wednesday Night | 45°F | Partly Cloudy | 1 mph NE | 3% |
| Thursday | 70°F | Partly Sunny | 2 mph NE | 7% |
| Thursday Night | 47°F | Partly Cloudy | 0 mph | 7% |
Forecast source: National Weather Service (api.weather.gov) for Ontario (43.722, -90.593). Updated through the day.
Growing snapshot for Ontario
Last spring frost
Apr 27
First fall frost
Oct 14
Growing season
170 days
Hardiness zone
4b
More local growing data for Ontario: nearby ZIP 54651 weather · frost dates · planting calendar · Wisconsin frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Cashton, Wi (10.7 mi from Ontario). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.