Grafton, IA Weather & Growing Conditions
Overnight
61°F
Patchy Fog
Patchy fog and a chance of showers and thunderstorms before 4am, then patchy fog and a chance of showers and thunderstorms. Cloudy, with a low around 61. East southeast wind around 10 mph. Chance of precipitation is 40%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 61°F | Patchy Fog | 10 mph ESE | 40% |
| Saturday | 71°F | Patchy Fog | 9 mph NE | 56% |
| Saturday Night | 56°F | Slight Chance Rain Showers | 9 to 13 mph NNE | 22% |
| Sunday | 66°F | Partly Sunny | 15 mph NE | 8% |
| Sunday Night | 50°F | Mostly Cloudy then Slight Chance Rain Showers | 13 mph ENE | 22% |
| Monday | 62°F | Chance Rain Showers | 13 mph ENE | 29% |
| Monday Night | 45°F | Slight Chance Rain Showers then Mostly Cloudy | 6 to 9 mph ENE | 22% |
| Tuesday | 61°F | Mostly Sunny | 6 to 9 mph ENE | 10% |
| Tuesday Night | 42°F | Mostly Clear | 6 mph E | 1% |
| Wednesday | 65°F | Sunny | 6 mph E | 1% |
| Wednesday Night | 47°F | Mostly Clear | 5 mph ESE | 5% |
| Thursday | 66°F | Mostly Sunny | 2 to 6 mph SE | 10% |
| Thursday Night | 50°F | Partly Cloudy | 3 mph ESE | 4% |
| Friday | 69°F | Mostly Sunny | 2 to 6 mph SE | 4% |
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 Sep 19, 2026.