Sister Bay, WI Weather & Growing Conditions
Today
81°F
Mostly Sunny then Chance Showers And Thunderstorms
A slight chance of rain showers between 2pm and 4pm, then a chance of showers and thunderstorms. Mostly sunny. High near 81, with temperatures falling to around 78 in the afternoon. Heat index values as high as 82. South southwest wind 8 to 13 mph, with gusts as high as 21 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 81°F | Mostly Sunny then Chance Showers And Thunderstorms | 8 to 13 mph SSW | 35% |
| Tonight | 61°F | Chance Showers And Thunderstorms | 3 to 8 mph NNE | 57% |
| Wednesday | 77°F | Partly Sunny | 5 mph ENE | 11% |
| Wednesday Night | 60°F | Partly Cloudy | 5 mph SE | 5% |
| Thursday | 80°F | Sunny | 2 to 8 mph SSW | 2% |
| Thursday Night | 63°F | Mostly Clear | 8 mph SSW | 0% |
| Friday | 82°F | Sunny | 6 to 13 mph SSW | 2% |
| Friday Night | 64°F | Slight Chance Rain Showers | 7 to 13 mph SSW | 16% |
| Saturday | 82°F | Mostly Sunny then Chance Showers And Thunderstorms | 9 mph SSW | 26% |
| Saturday Night | 64°F | Chance Showers And Thunderstorms | 3 to 8 mph SSW | 44% |
| Sunday | 80°F | Chance Showers And Thunderstorms | 3 to 9 mph SW | 44% |
| Sunday Night | 62°F | Chance Showers And Thunderstorms | 3 to 7 mph WSW | 32% |
| Monday | 80°F | Slight Chance Rain Showers | 6 mph SW | 24% |
| Monday Night | 62°F | Chance Rain Showers then Slight Chance Showers And Thunderstorms | 5 mph NE | 35% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Sister Bay, WI
Last spring frost
May 14
First fall frost
Oct 18
Growing season
155 days
Hardiness zone
5b
Explore more for Sister Bay, WI: full frost dates · planting calendar · Wisconsin frost dates
Climate data from the nearest NOAA station, Ephraim 1Ne-Wwtp, Wi (2.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.