Denison, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Denison, a city in Crawford County, Iowa.
Today
75°F
Showers And Thunderstorms
Showers and thunderstorms. Partly sunny. High near 75, with temperatures falling to around 73 in the afternoon. North northeast wind around 9 mph. Chance of precipitation is 80%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Denison
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 75°F | Showers And Thunderstorms | 9 mph NNE | 75% |
| Tonight | 57°F | Showers And Thunderstorms Likely | 2 to 8 mph NE | 67% |
| Wednesday | 73°F | Chance Showers And Thunderstorms | 6 mph ENE | 33% |
| Wednesday Night | 53°F | Mostly Clear | 0 to 3 mph E | 2% |
| Thursday | 80°F | Sunny | 0 to 5 mph SE | 1% |
| Thursday Night | 61°F | Mostly Clear | 5 mph SSE | 2% |
| Friday | 85°F | Mostly Sunny | 2 to 8 mph S | 3% |
| Friday Night | 65°F | Mostly Clear | 3 to 7 mph S | 8% |
| Saturday | 89°F | Mostly Sunny | 2 to 13 mph S | 4% |
| Saturday Night | 69°F | Mostly Clear | 8 to 13 mph S | 14% |
| Sunday | 89°F | Mostly Sunny | 10 mph SSE | 14% |
| Sunday Night | 69°F | Chance Showers And Thunderstorms | 10 mph SSE | 27% |
| Monday | 89°F | Chance Showers And Thunderstorms then Partly Sunny | 13 mph SSE | 27% |
| Monday Night | 70°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 9 to 14 mph ESE | 21% |
Forecast source: National Weather Service (api.weather.gov) for Denison (42.016, -95.353). Updated through the day.
Growing snapshot for Denison
Last spring frost
Apr 27
First fall frost
Oct 11
Growing season
166 days
Hardiness zone
5a
More local growing data for Denison: nearby ZIP 51442 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Arion
Aspinwall
Buck Grove
Charter Oak
Deloit
Dow City
Kiron
Manilla
Ricketts
Schleswig
Vail
Westside
Climate data from the nearest NOAA station, Denison, Ia (1.5 mi from Denison). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.