Denison, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Denison, a city in Crawford County, Iowa.
This Afternoon
57°F
Rain Showers
Rain showers. Cloudy. High near 57, with temperatures falling to around 53 in the afternoon. North northwest wind around 16 mph, with gusts as high as 26 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 |
|---|---|---|---|---|
| This Afternoon | 57°F | Rain Showers | 16 mph NNW | 79% |
| Tonight | 39°F | Rain Showers | 9 to 13 mph NW | 85% |
| Wednesday | 48°F | Chance Rain Showers | 10 to 14 mph WNW | 42% |
| Wednesday Night | 38°F | Cloudy then Chance Rain Showers | 6 to 10 mph WNW | 54% |
| Thursday | 51°F | Chance Rain Showers | 9 mph NNW | 53% |
| Thursday Night | 34°F | Mostly Cloudy | 2 to 6 mph N | 4% |
| Friday | 50°F | Partly Sunny | 2 mph N | 0% |
| Friday Night | 32°F | Mostly Cloudy | 0 mph | 0% |
| Saturday | 56°F | Mostly Sunny | 0 to 5 mph WSW | 2% |
| Saturday Night | 35°F | Mostly Clear | 2 mph W | 4% |
| Sunday | 62°F | Sunny | 1 to 5 mph WSW | 5% |
| Sunday Night | 38°F | Mostly Clear | 5 mph SSW | 0% |
| Monday | 64°F | Sunny | 5 to 8 mph WSW | 0% |
| Monday Night | 39°F | Mostly Clear | 1 to 5 mph NW | 0% |
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 Nov 4, 2026.