Waterloo, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Waterloo, a city in Jefferson County, Wisconsin.
This Afternoon
70°F
Rain Showers Likely
Rain showers likely. Mostly cloudy. High near 70, with temperatures falling to around 64 in the afternoon. East wind around 10 mph. Chance of precipitation is 70%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Waterloo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 70°F | Rain Showers Likely | 10 mph E | 70% |
| Tonight | 59°F | Showers And Thunderstorms | 10 to 15 mph E | 100% |
| Saturday | 72°F | Showers And Thunderstorms | 10 mph SE | 95% |
| Saturday Night | 58°F | Showers And Thunderstorms | 10 mph NE | 76% |
| Sunday | 68°F | Chance Rain Showers | 10 to 15 mph NE | 34% |
| Sunday Night | 52°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 17% |
| Monday | 64°F | Mostly Cloudy then Slight Chance Rain Showers | 10 to 15 mph NE | 17% |
| Monday Night | 48°F | Slight Chance Rain Showers | 5 to 10 mph NE | 17% |
| Tuesday | 62°F | Slight Chance Rain Showers then Partly Sunny | 10 to 15 mph NE | 15% |
| Tuesday Night | 46°F | Partly Cloudy | 5 to 10 mph NE | 7% |
| Wednesday | 66°F | Mostly Sunny | 5 to 10 mph NE | 5% |
| Wednesday Night | 48°F | Partly Cloudy | 0 to 5 mph NE | 2% |
| Thursday | 69°F | Mostly Sunny | 0 to 5 mph NE | 4% |
| Thursday Night | 50°F | Partly Cloudy | 0 to 5 mph N | 5% |
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.