Jefferson, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Jefferson, a city in Greene County, Iowa.
Today
79°F
Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 8am, then patchy fog and a chance of showers and thunderstorms between 8am and 11am, then a slight chance of showers and thunderstorms between 11am and 5pm. Mostly cloudy. High near 79, with temperatures falling to around 74 in the afternoon. Northwest wind 3 to 7 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Jefferson
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 79°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 3 to 7 mph NW | 41% |
| Tonight | 60°F | Slight Chance Showers And Thunderstorms | 8 mph N | 27% |
| Sunday | 66°F | Chance Drizzle | 10 mph NNE | 42% |
| Sunday Night | 55°F | Chance Rain Showers | 9 mph ENE | 46% |
| Monday | 62°F | Rain Showers Likely | 9 mph ENE | 58% |
| Monday Night | 50°F | Chance Rain Showers | 3 to 7 mph NE | 53% |
| Tuesday | 62°F | Partly Sunny | 6 mph ENE | 8% |
| Tuesday Night | 45°F | Partly Cloudy | 3 mph E | 1% |
| Wednesday | 66°F | Mostly Sunny | 3 mph ESE | 1% |
| Wednesday Night | 50°F | Partly Cloudy | 2 mph ESE | 10% |
| Thursday | 67°F | Slight Chance Rain Showers | 1 to 5 mph SE | 18% |
| Thursday Night | 53°F | Mostly Cloudy | 2 mph ESE | 9% |
| Friday | 69°F | Mostly Cloudy | 1 to 6 mph ESE | 9% |
| Friday Night | 55°F | Mostly Cloudy | 3 mph SE | 11% |
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 Sep 19, 2026.