Lyndon, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Lyndon, a village in Whiteside County, Illinois.
Today
87°F
Mostly Sunny
Mostly sunny. High near 87, with temperatures falling to around 85 in the afternoon. Southwest wind around 10 mph.
7-day forecast for Lyndon
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Mostly Sunny | 10 mph SW | 6% |
| Tonight | 67°F | Showers And Thunderstorms Likely | 5 mph NW | 82% |
| Wednesday | 78°F | Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 mph W | 79% |
| Wednesday Night | 62°F | Showers And Thunderstorms | 0 to 5 mph N | 79% |
| Thursday | 79°F | Chance Rain Showers | 5 mph NE | 43% |
| Thursday Night | 60°F | Mostly Clear | 0 to 5 mph NE | 12% |
| Friday | 82°F | Mostly Sunny | 0 to 5 mph S | 4% |
| Friday Night | 64°F | Mostly Clear | 0 to 5 mph S | 8% |
| Saturday | 85°F | Sunny | 5 to 10 mph S | 10% |
| Saturday Night | 70°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 5 to 10 mph S | 19% |
| Sunday | 87°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 to 15 mph SW | 19% |
| Sunday Night | 69°F | Chance Showers And Thunderstorms | 5 to 10 mph S | 36% |
| Monday | 86°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 5 to 10 mph S | 36% |
| Monday Night | 69°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 10 mph W | 38% |
Forecast source: National Weather Service (api.weather.gov) for Lyndon (41.718, -89.924). Updated through the day.
Growing snapshot for Lyndon
Last spring frost
Apr 26
First fall frost
Oct 13
Growing season
167 days
Hardiness zone
5b
More local growing data for Lyndon: nearby ZIP 61261 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Morrison, Il (5 mi from Lyndon). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.