Jefferson, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Jefferson, a city in Greene County, Iowa.
Tonight
43°F
Rain Showers
Rain showers before 5am. Cloudy. Low around 43, with temperatures rising to around 45 overnight. Northwest wind 9 to 16 mph, with gusts as high as 23 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Jefferson
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 43°F | Rain Showers | 9 to 16 mph NW | 81% |
| Wednesday | 50°F | Chance Rain Showers | 13 mph W | 28% |
| Wednesday Night | 41°F | Cloudy then Chance Rain Showers | 9 mph W | 48% |
| Thursday | 51°F | Rain Showers Likely | 9 mph NW | 56% |
| Thursday Night | 37°F | Mostly Cloudy | 3 to 7 mph N | 12% |
| Friday | 52°F | Partly Sunny | 1 to 5 mph N | 2% |
| Friday Night | 32°F | Mostly Cloudy | 1 mph NNW | 0% |
| Saturday | 57°F | Mostly Sunny | 0 to 3 mph WSW | 2% |
| Saturday Night | 36°F | Mostly Clear | 2 mph W | 4% |
| Sunday | 62°F | Sunny | 5 mph W | 5% |
| Sunday Night | 39°F | Mostly Clear | 3 mph SW | 1% |
| Monday | 65°F | Sunny | 3 to 8 mph WSW | 0% |
| Monday Night | 40°F | Mostly Clear | 5 mph WNW | 0% |
| Tuesday | 63°F | Mostly Sunny | 5 mph WNW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Jefferson (42.018, -94.379). Updated through the day.
Growing snapshot for Jefferson
Last spring frost
Apr 26
First fall frost
Oct 9
Growing season
164 days
Hardiness zone
5b
More local growing data for Jefferson: nearby ZIP 50129 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Jefferson, Ia (1 mi from Jefferson). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.