Prophetstown, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Prophetstown, a city in Whiteside County, Illinois.
Tonight
65°F
Mostly Cloudy then Chance Showers And Thunderstorms
A chance of showers and thunderstorms between 1am and 5am, then showers and thunderstorms likely. Mostly cloudy. Low around 65, with temperatures rising to around 67 overnight. East wind around 10 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Prophetstown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 65°F | Mostly Cloudy then Chance Showers And Thunderstorms | 10 mph E | 57% |
| Saturday | 81°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SE | 74% |
| Saturday Night | 64°F | Showers And Thunderstorms | 5 to 10 mph NW | 80% |
| Sunday | 71°F | Showers And Thunderstorms Likely | 10 to 15 mph NE | 80% |
| Sunday Night | 56°F | Showers And Thunderstorms Likely | 15 mph NE | 64% |
| Monday | 65°F | Rain Showers Likely | 15 mph NE | 55% |
| Monday Night | 51°F | Chance Rain Showers | 10 to 15 mph NE | 46% |
| Tuesday | 63°F | Chance Rain Showers | 15 mph NE | 33% |
| Tuesday Night | 48°F | Mostly Cloudy | 5 to 15 mph NE | 5% |
| Wednesday | 67°F | Mostly Sunny | 5 to 10 mph NE | 3% |
| Wednesday Night | 51°F | Partly Cloudy | 5 mph NE | 3% |
| Thursday | 69°F | Mostly Sunny | 5 mph NE | 4% |
| Thursday Night | 53°F | Partly Cloudy | 0 to 5 mph NE | 5% |
| Friday | 71°F | Mostly Sunny | 0 to 5 mph NE | 5% |
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 Sep 19, 2026.