Prophetstown, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Prophetstown, a city in Whiteside County, Illinois.
Overnight
60°F
Mostly Clear
Mostly clear. Low around 60, with temperatures rising to around 62 overnight. South wind around 5 mph.
7-day forecast for Prophetstown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 60°F | Mostly Clear | 5 mph S | 0% |
| Tuesday | 86°F | Mostly Sunny | 5 to 10 mph SW | 7% |
| Tuesday Night | 67°F | Showers And Thunderstorms Likely | 5 mph NW | 69% |
| Wednesday | 78°F | Showers And Thunderstorms Likely | 5 mph W | 71% |
| Wednesday Night | 62°F | Showers And Thunderstorms | 0 to 5 mph N | 79% |
| Thursday | 79°F | Chance Rain Showers | 5 mph NE | 44% |
| Thursday Night | 60°F | Mostly Clear | 0 to 5 mph E | 13% |
| Friday | 81°F | Mostly Sunny | 0 to 5 mph SE | 5% |
| Friday Night | 64°F | Mostly Clear | 0 to 5 mph S | 8% |
| Saturday | 85°F | Sunny | 5 to 10 mph SW | 10% |
| Saturday Night | 69°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 5 to 10 mph S | 18% |
| Sunday | 87°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 to 15 mph SW | 18% |
| 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% |
Forecast source: National Weather Service (api.weather.gov) for Prophetstown (41.670, -89.935). Updated through the day.
Growing snapshot for Prophetstown
Last spring frost
Apr 26
First fall frost
Oct 13
Growing season
167 days
Hardiness zone
5b
More local growing data for Prophetstown: nearby ZIP 61277 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Morrison, Il (12.6 mi from Prophetstown). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.