Lannon, WI Weather & Growing Conditions
Tonight
58°F
Rain Showers
Rain showers. Cloudy, with a low around 58. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 58°F | Rain Showers | 10 to 15 mph S | 86% |
| Wednesday | 63°F | Rain Showers | 10 to 15 mph S | 85% |
| Wednesday Night | 47°F | Chance Rain Showers then Chance Light Rain | 10 to 15 mph SW | 41% |
| Thursday | 55°F | Light Rain Likely | 5 to 15 mph W | 63% |
| Thursday Night | 40°F | Chance Light Rain | 5 to 10 mph NW | 53% |
| Friday | 49°F | Slight Chance Light Rain | 10 to 15 mph N | 24% |
| Friday Night | 34°F | Mostly Cloudy | 0 to 5 mph N | 6% |
| Saturday | 52°F | Mostly Sunny | 0 to 5 mph W | 3% |
| Saturday Night | 34°F | Partly Cloudy | 0 to 5 mph W | 8% |
| Sunday | 57°F | Slight Chance Light Rain | 5 to 10 mph W | 18% |
| Sunday Night | 36°F | Partly Cloudy | 5 mph W | 5% |
| Monday | 59°F | Mostly Sunny | 5 to 15 mph SW | 2% |
| Monday Night | 40°F | Partly Cloudy | 5 to 10 mph W | 2% |
| Tuesday | 59°F | Sunny | 5 to 10 mph NW | 0% |
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 Nov 4, 2026.