Lake Koshkonong, WI Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Lake Koshkonong, a community in Rock County, Wisconsin.

This Afternoon

68°F

Light Rain

Rain and a slight chance of thunderstorms. Cloudy, with a high near 68. South wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 100%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast for Lake Koshkonong

When	Temp	Forecast	Wind	Precip
This Afternoon	68°F	Light Rain	15 to 20 mph S	97%
Tonight	56°F	Light Rain	15 mph S	86%
Wednesday	61°F	Light Rain	10 to 15 mph SW	79%
Wednesday Night	46°F	Chance Light Rain	15 mph SW	46%
Thursday	53°F	Light Rain Likely	10 to 15 mph W	71%
Thursday Night	39°F	Chance Light Rain	10 to 15 mph NW	43%
Friday	48°F	Slight Chance Light Rain then Mostly Cloudy	10 to 15 mph N	17%
Friday Night	32°F	Partly Cloudy	0 to 10 mph N	1%
Saturday	51°F	Mostly Sunny	0 to 5 mph W	4%
Saturday Night	33°F	Partly Cloudy	0 to 5 mph W	7%
Sunday	57°F	Slight Chance Light Rain	5 to 10 mph W	17%
Sunday Night	34°F	Mostly Clear	5 to 10 mph W	5%
Monday	59°F	Sunny	5 to 15 mph SW	1%
Monday Night	38°F	Mostly Clear	5 to 10 mph W	1%

Forecast source: National Weather Service (api.weather.gov) for Lake Koshkonong (42.861, -88.940). Updated through the day.

Growing snapshot for Lake Koshkonong

Last spring frost

Apr 28

First fall frost

Oct 13

Growing season

166 days

Hardiness zone

More local growing data for Lake Koshkonong: nearby ZIP 53563 weather · frost dates · planting calendar · Wisconsin frost dates

Nearby towns & communities

Brodhead Clinton Edgerton Evansville Footville Fulton Hanover Janesville Milton Orfordville Shopiere

All Wisconsin locations ›

Climate data from the nearest NOAA station, Ft Atkinson, Wi (9.4 mi from Lake Koshkonong). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.