Lake Koshkonong, WI Weather & Growing Conditions
This Afternoon
70°F
Rain Showers Likely
Rain showers likely. Mostly cloudy, with a high near 70. East wind around 10 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 70°F | Rain Showers Likely | 10 mph E | 60% |
| Tonight | 60°F | Showers And Thunderstorms Likely | 10 to 15 mph E | 94% |
| Saturday | 73°F | Showers And Thunderstorms | 10 to 15 mph SE | 93% |
| Saturday Night | 59°F | Showers And Thunderstorms Likely | 5 to 10 mph NE | 74% |
| Sunday | 67°F | Chance Rain Showers | 10 to 15 mph NE | 47% |
| Sunday Night | 52°F | Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 29% |
| Monday | 63°F | Slight Chance Rain Showers | 10 to 15 mph NE | 19% |
| Monday Night | 48°F | Slight Chance Rain Showers | 10 to 15 mph NE | 19% |
| Tuesday | 62°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 16% |
| Tuesday Night | 46°F | Partly Cloudy | 5 to 10 mph NE | 8% |
| Wednesday | 65°F | Mostly Sunny | 5 to 10 mph NE | 7% |
| Wednesday Night | 48°F | Partly Cloudy | 0 to 5 mph NE | 2% |
| Thursday | 67°F | Partly Sunny | 0 to 5 mph NE | 4% |
| Thursday Night | 49°F | Partly Cloudy | 0 to 5 mph NE | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Lake Koshkonong, WI
Last spring frost
Apr 28
First fall frost
Oct 13
Growing season
166 days
Hardiness zone
5b
Explore more for Lake Koshkonong, WI: full frost dates · planting calendar · Wisconsin frost dates
Climate data from the nearest NOAA station, Ft Atkinson, Wi (0.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.