Jefferson, IA Weather & Growing Conditions
Tonight
66°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Mostly cloudy. Low around 66, with temperatures rising to around 68 overnight. South southwest wind 5 to 8 mph. Chance of precipitation is 50%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 66°F | Chance Showers And Thunderstorms | 5 to 8 mph SSW | 51% |
| Saturday | 79°F | Chance Showers And Thunderstorms | 7 mph WNW | 47% |
| Saturday Night | 60°F | Chance Showers And Thunderstorms | 8 mph N | 27% |
| Sunday | 68°F | Chance Rain Showers | 10 mph NNE | 46% |
| Sunday Night | 55°F | Chance Rain Showers | 9 mph ENE | 47% |
| Monday | 61°F | Rain Showers Likely | 9 mph ENE | 70% |
| Monday Night | 50°F | Rain Showers Likely | 5 to 8 mph NE | 59% |
| Tuesday | 62°F | Mostly Cloudy | 6 mph ENE | 13% |
| Tuesday Night | 46°F | Partly Cloudy | 1 to 5 mph E | 2% |
| Wednesday | 66°F | Mostly Sunny | 3 mph E | 4% |
| Wednesday Night | 50°F | Mostly Cloudy | 2 mph E | 9% |
| Thursday | 68°F | Slight Chance Rain Showers | 3 mph SE | 21% |
| Thursday Night | 54°F | Mostly Cloudy then Slight Chance Rain Showers | 1 mph SE | 15% |
| Friday | 69°F | Slight Chance Rain Showers then Partly Sunny | 1 to 5 mph ESE | 15% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Jefferson, IA
Last spring frost
Apr 26
First fall frost
Oct 9
Growing season
164 days
Hardiness zone
5b
Explore more for Jefferson, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Jefferson, Ia (1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.