Denison, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Denison, a city in Crawford County, Iowa.
This Afternoon
72°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 5pm. Mostly cloudy. High near 72, with temperatures falling to around 69 in the afternoon. North wind around 9 mph. Chance of precipitation is 20%.
7-day forecast for Denison
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 72°F | Slight Chance Showers And Thunderstorms | 9 mph N | 15% |
| Tonight | 59°F | Slight Chance Showers And Thunderstorms then Mostly Cloudy | 6 to 9 mph NNE | 15% |
| Sunday | 63°F | Chance Drizzle then Chance Rain Showers | 7 to 12 mph NE | 42% |
| Sunday Night | 53°F | Rain Showers Likely | 8 mph NE | 68% |
| Monday | 57°F | Rain Showers | 8 mph NE | 83% |
| Monday Night | 48°F | Rain Showers Likely then Mostly Cloudy | 2 to 7 mph NE | 73% |
| Tuesday | 60°F | Partly Sunny | 6 mph ENE | 3% |
| Tuesday Night | 45°F | Partly Cloudy | 3 mph E | 0% |
| Wednesday | 64°F | Mostly Sunny | 1 to 5 mph ESE | 2% |
| Wednesday Night | 51°F | Mostly Cloudy then Slight Chance Showers And Thunderstorms | 2 mph SE | 24% |
| Thursday | 66°F | Chance Showers And Thunderstorms | 2 to 7 mph SSE | 36% |
| Thursday Night | 56°F | Slight Chance Rain Showers | 3 mph SE | 24% |
| Friday | 69°F | Slight Chance Rain Showers | 1 to 5 mph ESE | 18% |
| Friday Night | 58°F | Mostly Cloudy then Chance Rain Showers | 3 mph SE | 26% |
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 Sep 19, 2026.