Weather World
Town of Sullivan, WISullivan, WI 7-Day Night Weather Forecast
Quick Weather Clicks
Settings
Sun & Moon
Weather Quote O' the Day
Sullivan, WI Weather Forecast
Sullivan, WI Weather Forecast Date: 731 AM CDT Fri Sep 04 2026
The area/counties/county of: Jefferson, including the cities of: Watertown, Fort Atkinson, and Jefferson.or toggle through each period.
Today... Warm and humid. Mostly cloudy in the morning then becoming partly sunny. Chance of light showers and thunderstorms in the morning. Slight chance of light showers and thunderstorms late in the afternoon. Highs in the upper 80s. South winds up to 5 mph shifting to the southwest around 5 mph in the afternoon. Chance of precipitation 30%. Highest heat index readings 95 to 98 in the afternoon.
Tonight... Partly cloudy. A 50% chance of light showers and thunderstorms through around midnight. Patchy fog after midnight. Lows in the upper 60s. Southwest winds up to 5 mph shifting to the north after midnight.
Saturday... Partly sunny. Patchy fog in the morning. Highs in the lower 80s. Northeast winds up to 10 mph.
Saturday Night... Partly cloudy. Lows in the lower 60s. Northeast winds up to 10 mph.
Sunday... Partly sunny. Highs in the lower 80s. East winds up to 10 mph.
Sunday Night... Partly cloudy. Lows around 60.
Labor Day... Partly sunny. Highs in the lower 80s.
Monday Night... Mostly cloudy. A 20% chance of light showers after midnight. Lows in the lower 60s.
Tuesday... Mostly cloudy. Chance of light showers in the morning, then slight chance of light showers and thunderstorms in the afternoon. Highs in the lower 80s. Chance of precipitation 40%.
Tuesday Night... Partly cloudy with chance of light showers and slight chance of thunderstorms through around midnight, then mostly cloudy with light showers likely and slight chance of thunderstorms after midnight. Lows in the upper 60s. Chance of precipitation 60%.
Wednesday... Partly sunny. A 20% chance of light showers and thunderstorms in the morning. Highs in the mid 80s.
Wednesday Night... Partly cloudy. Slight chance of light showers through around midnight, then chance of light showers and slight chance of thunderstorms after midnight. Lows in the mid 60s. Chance of precipitation 30%.
POP = Probability of Precipitation
Sullivan Radar Loop
Use the map search tool if you want to place a location marker on the radar map...