Jefferson, IA Weather & Growing Conditions
Today
79°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Mostly cloudy. High near 79, with temperatures falling to around 76 in the afternoon. North northwest wind 3 to 9 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 79°F | Chance Showers And Thunderstorms | 3 to 9 mph NNW | 44% |
| Tonight | 60°F | Showers And Thunderstorms | 5 to 9 mph NNE | 86% |
| Wednesday | 74°F | Chance Showers And Thunderstorms | 6 mph NE | 37% |
| Wednesday Night | 54°F | Partly Cloudy | 0 to 3 mph E | 6% |
| Thursday | 82°F | Sunny | 0 to 5 mph ESE | 1% |
| Thursday Night | 60°F | Mostly Clear | 3 mph SSE | 2% |
| Friday | 87°F | Sunny | 2 to 8 mph S | 6% |
| Friday Night | 66°F | Mostly Clear | 3 to 7 mph S | 12% |
| Saturday | 91°F | Sunny | 2 to 10 mph S | 11% |
| Saturday Night | 70°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 10 mph S | 16% |
| Sunday | 91°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 mph SSE | 16% |
| Sunday Night | 70°F | Slight Chance Showers And Thunderstorms | 6 to 10 mph SSE | 30% |
| Monday | 90°F | Chance Showers And Thunderstorms then Partly Sunny | 12 mph SSE | 30% |
| Monday Night | 70°F | Slight Chance Showers And Thunderstorms | 9 to 13 mph ESE | 23% |
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 Aug 4, 2026.