Prophetstown, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Prophetstown, a city in Whiteside County, Illinois.
Tonight
53°F
Rain Showers Likely
Rain showers likely. Mostly cloudy. Low around 53, with temperatures rising to around 56 overnight. South wind 10 to 15 mph, with gusts as high as 25 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 | 53°F | Rain Showers Likely | 10 to 15 mph S | 55% |
| Wednesday | 57°F | Chance Rain Showers | 15 mph SW | 28% |
| Wednesday Night | 46°F | Mostly Cloudy | 10 to 15 mph SW | 14% |
| Thursday | 55°F | Chance Rain Showers | 10 to 15 mph W | 42% |
| Thursday Night | 41°F | Slight Chance Rain Showers then Mostly Cloudy | 10 mph NW | 19% |
| Friday | 50°F | Partly Sunny | 5 to 10 mph N | 7% |
| Friday Night | 31°F | Partly Cloudy | 0 to 5 mph N | 0% |
| Saturday | 51°F | Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 33°F | Mostly Clear | 0 to 5 mph W | 2% |
| Sunday | 56°F | Sunny | 5 to 10 mph W | 3% |
| Sunday Night | 34°F | Mostly Clear | 0 to 5 mph W | 1% |
| Monday | 62°F | Sunny | 0 to 10 mph SW | 0% |
| Monday Night | 39°F | Mostly Clear | 5 mph W | 0% |
| Tuesday | 63°F | Sunny | 5 mph NW | 0% |
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 Nov 4, 2026.