Lannon, WI Weather & Growing Conditions
Today
83°F
Mostly Sunny
Mostly sunny, with a high near 83. Southwest wind around 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 83°F | Mostly Sunny | 10 mph SW | 7% |
| Tonight | 64°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 5 to 10 mph W | 87% |
| Wednesday | 74°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 5 mph W | 68% |
| Wednesday Night | 60°F | Chance Showers And Thunderstorms | 0 to 5 mph NE | 43% |
| Thursday | 78°F | Slight Chance Rain Showers then Mostly Sunny | 0 to 5 mph NE | 20% |
| Thursday Night | 59°F | Mostly Clear | 0 to 5 mph S | 8% |
| Friday | 82°F | Sunny | 0 to 5 mph SW | 1% |
| Friday Night | 63°F | Mostly Clear | 0 to 5 mph SW | 6% |
| Saturday | 84°F | Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 15% |
| Saturday Night | 68°F | Slight Chance Showers And Thunderstorms | 5 mph SW | 28% |
| Sunday | 85°F | Chance Showers And Thunderstorms | 5 to 10 mph SW | 28% |
| Sunday Night | 66°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 to 10 mph SW | 52% |
| Monday | 83°F | Chance Rain Showers | 5 mph S | 42% |
| Monday Night | 66°F | Chance Showers And Thunderstorms | 0 to 5 mph N | 43% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Lannon, WI
Last spring frost
Apr 30
First fall frost
Oct 16
Growing season
167 days
Hardiness zone
5b
Explore more for Lannon, WI: full frost dates · planting calendar · Wisconsin frost dates
Climate data from the nearest NOAA station, Richfield 3 Ssw, Wi (4.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.