Grafton, IA Weather & Growing Conditions
Tonight
45°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy. Low around 45, with temperatures rising to around 50 overnight. South southeast wind 7 to 10 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 45°F | Showers And Thunderstorms | 7 to 10 mph SSE | 86% |
| Wednesday | 51°F | Rain Showers | 10 to 15 mph WSW | 87% |
| Wednesday Night | 41°F | Rain Showers | 14 mph W | 86% |
| Thursday | 49°F | Rain Showers Likely | 14 mph NNW | 65% |
| Thursday Night | 34°F | Mostly Cloudy | 7 to 12 mph N | 10% |
| Friday | 47°F | Partly Sunny | 3 to 8 mph NNE | 1% |
| Friday Night | 28°F | Partly Cloudy | 2 mph ENE | 1% |
| Saturday | 52°F | Mostly Sunny | 1 to 7 mph SW | 1% |
| Saturday Night | 33°F | Partly Cloudy | 6 mph W | 5% |
| Sunday | 57°F | Sunny | 8 mph WNW | 7% |
| Sunday Night | 35°F | Mostly Clear | 7 mph SW | 1% |
| Monday | 60°F | Mostly Sunny | 7 to 12 mph WSW | 0% |
| Monday Night | 38°F | Mostly Clear | 7 mph WNW | 1% |
| Tuesday | 58°F | Mostly Sunny | 7 mph WNW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Grafton, IA
Last spring frost
May 4
First fall frost
Oct 4
Growing season
152 days
Hardiness zone
5a
Explore more for Grafton, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Northwood, Ia (10.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.