Denison (IA) Weather & Climate: Best Time to Visit

Average temperatures, rainfall, sunshine and the best time to visit Denison.

Climate overview of Denison

Denison, Iowa, United States of America, experiences significant temperature variation throughout the year. Summers bring daytime highs of 29°C (84°F) in July, while winters cool to -2°C (28°F) in January.

The city receives around 923 mm (36 in) of rain/snowfall per year. It experiences a distinct dry season from January to March. August is the wettest month and January the driest.

Denison Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in Denison — and find the best time to visit.

Monthly Temperature in Denison

Depending on the time of the year, temperatures range from comfortable to very cold in Denison. On average, daytime temperatures range from a comfortable 29°C (84°F) in July to a very cold -2°C (28°F) in January.

Nighttime temperatures range from 17°C (63°F) in July to -12°C (10°F) in January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Rainfall in Denison

Generally, Denison has a moderate amount of precipitation, averaging 923 mm (36 in) of rain/snowfall annually. The seasons in Denison bring significant changes in precipitation. The wettest month, August, receives high rainfall, with an average of 140 mm (5.5 in) of precipitation. This rainfall is distributed across 11 rainy days.

In contrast, the driest month, January, experiences much less snowfall, totaling 16 mm (0.6 in) over 6 snowy days. These distinct seasonal differences provide diverse experiences throughout the year. For more details, please visit our Denison Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

Best Time to Visit Denison

During the months of May, June, July, August and September, Denison enjoys pleasant weather with average temperatures ranging from 22°C (72°F) to 29°C (84°F). These months are perfect for sightseeing and exploring.

Rainfall during this time ranges from 89 mm (3.5 in) in September to 140 mm (5.5 in) in August. This means you can expect a mix of sunny days and occasional showers.

Seeking the perfect travel destination for this year? We've created a tool that suggests locations matching your desired weather. Let our weather planner guide your travel decisions.

Frequently asked questions about the climate in Denison

What is the best time to visit Denison?

September typically offers the most optimal weather in Denison. In contrast, January, February, March, November and December tend to have less optimal conditions. Denison has a distinct dry season from January to March.

What temperatures can I expect in Denison?

Daytime highs range from -2°C (28°F) in January to 29°C (84°F) in July. Nighttime lows range from -12°C (10°F) to 17°C (63°F). Temperatures vary considerably through the year.

How much rain does Denison get?

Annual rainfall is around 923 mm (36 in). August is the wettest month with 140 mm (5.5 in), while January is the driest with 16 mm (0.6 in).

Denison 3-Day Forecast

Denison (IA) 3-Day Forecast

Denison on the map

Denison is highlighted — select any city to see its climate.

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