Denison, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Denison, a city in Crawford County, Iowa.
Overnight
66°F
Patchy Fog
Patchy fog and a chance of showers and thunderstorms. Cloudy. Low around 66, with temperatures rising to around 69 overnight. West northwest wind around 6 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Denison
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 66°F | Patchy Fog | 6 mph WNW | 51% |
| Saturday | 75°F | Patchy Fog then Mostly Cloudy | 3 to 7 mph NNW | 49% |
| Saturday Night | 59°F | Slight Chance Rain Showers then Slight Chance Drizzle | 8 mph NNE | 16% |
| Sunday | 63°F | Slight Chance Drizzle then Chance Rain Showers | 8 to 12 mph NE | 34% |
| Sunday Night | 54°F | Chance Rain Showers | 8 mph ENE | 45% |
| Monday | 59°F | Rain Showers Likely | 8 mph ENE | 58% |
| Monday Night | 49°F | Chance Rain Showers then Mostly Cloudy | 2 to 7 mph ENE | 45% |
| Tuesday | 60°F | Partly Sunny | 2 to 6 mph ENE | 8% |
| Tuesday Night | 45°F | Partly Cloudy | 3 mph ESE | 1% |
| Wednesday | 64°F | Mostly Sunny | 1 to 5 mph SE | 2% |
| Wednesday Night | 50°F | Partly Cloudy then Slight Chance Rain Showers | 2 mph SE | 23% |
| Thursday | 65°F | Slight Chance Rain Showers | 1 to 6 mph SE | 23% |
| Thursday Night | 54°F | Mostly Cloudy then Slight Chance Rain Showers | 3 mph SE | 15% |
| Friday | 68°F | Slight Chance Rain Showers then Mostly Cloudy | 1 to 6 mph SE | 15% |
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.