Waterloo, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Waterloo, a city in Jefferson County, Wisconsin.
Today
69°F
Chance Showers And Thunderstorms then Showers And Thunderstorms
A chance of showers and thunderstorms before 11am, then showers and thunderstorms. Cloudy, with a high near 69. Southeast wind 5 to 10 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast for Waterloo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 69°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 5 to 10 mph SE | 78% |
| Tonight | 59°F | Showers And Thunderstorms | 5 to 10 mph NE | 79% |
| Sunday | 66°F | Chance Rain Showers then Cloudy | 10 to 15 mph NE | 45% |
| Sunday Night | 51°F | Mostly Cloudy | 10 to 15 mph NE | 2% |
| Monday | 63°F | Mostly Cloudy | 10 to 15 mph NE | 12% |
| Monday Night | 47°F | Mostly Cloudy | 5 to 10 mph NE | 12% |
| Tuesday | 62°F | Partly Sunny | 5 to 15 mph NE | 7% |
| Tuesday Night | 46°F | Partly Cloudy | 5 to 10 mph NE | 4% |
| Wednesday | 65°F | Mostly Sunny | 5 to 10 mph NE | 3% |
| Wednesday Night | 48°F | Partly Cloudy | 0 to 5 mph NE | 1% |
| Thursday | 67°F | Mostly Sunny | 5 mph NE | 4% |
| Thursday Night | 49°F | Partly Cloudy | 0 to 5 mph NE | 4% |
| Friday | 71°F | Mostly Sunny | 0 to 5 mph NE | 3% |
| Friday Night | 49°F | Partly Cloudy | 0 to 5 mph E | 2% |
Forecast source: National Weather Service (api.weather.gov) for Waterloo (43.184, -88.990). Updated through the day.
Growing snapshot for Waterloo
Last spring frost
Apr 30
First fall frost
Oct 9
Growing season
163 days
Hardiness zone
5b
More local growing data for Waterloo: nearby ZIP 53594 weather · frost dates · planting calendar · Wisconsin frost dates
Nearby towns & communities
Fort Atkinson
Hebron
Helenville
Ixonia
Jefferson
Johnson Creek
Lake Mills
Palmyra
Rome
Sullivan
Watertown
Climate data from the nearest NOAA station, Waterloo Wwtp, Wi (0.8 mi from Waterloo). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.