Winthrop Harbor, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Winthrop Harbor, a village in Lake County, Illinois.
Today
81°F
Mostly Sunny
Mostly sunny, with a high near 81. South wind around 10 mph.
7-day forecast for Winthrop Harbor
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 81°F | Mostly Sunny | 10 mph S | 0% |
| Tonight | 67°F | Mostly Cloudy then Chance Showers And Thunderstorms | 5 to 10 mph SW | 48% |
| Wednesday | 77°F | Showers And Thunderstorms Likely | 5 mph NW | 74% |
| Wednesday Night | 62°F | Showers And Thunderstorms | 5 mph NW | 76% |
| Thursday | 76°F | Chance Rain Showers | 5 mph NNE | 50% |
| Thursday Night | 62°F | Partly Cloudy | 0 to 5 mph S | 12% |
| Friday | 80°F | Mostly Sunny | 5 mph SSW | 3% |
| Friday Night | 64°F | Mostly Clear | 5 mph S | 8% |
| Saturday | 82°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 15% |
| Saturday Night | 68°F | Slight Chance Showers And Thunderstorms | 5 mph SW | 23% |
| Sunday | 83°F | Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 23% |
| Sunday Night | 67°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 to 10 mph WSW | 47% |
| Monday | 82°F | Chance Rain Showers | 5 to 10 mph S | 47% |
| Monday Night | 67°F | Chance Showers And Thunderstorms | 5 mph SE | 48% |
Forecast source: National Weather Service (api.weather.gov) for Winthrop Harbor (42.481, -87.830). Updated through the day.
Growing snapshot for Winthrop Harbor
Last spring frost
Apr 30
First fall frost
Oct 21
Growing season
173 days
Hardiness zone
6a
More local growing data for Winthrop Harbor: nearby ZIP 60096 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Antioch
Bannockburn
Beach Park
Buffalo Grove
Burtons Bridge
Deer Park
Deerfield
Forest Lake
Fox Lake
Fox Lake Hills
Gages Lake
Grandwood Park
Grayslake
Green Oaks
Gurnee
Hainesville
Hawthorn Woods
Highland Park
Highwood
Holiday Hills
Indian Creek
Island Lake
Kildeer
Knollwood
Lake Bluff
Lake Forest
Lake Villa
Lake Zurich
Libertyville
Lincolnshire
Climate data from the nearest NOAA station, Chicago Waukegan Rgnl Ap, Il (4.8 mi from Winthrop Harbor). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.