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

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

Climate overview of Grinnell

The climate in Grinnell, Iowa, United States of America, is marked by large temperature swings across the seasons, ranging from 29°C (84°F) in July to -2°C (28°F) in January.

Rain/snowfall is high, totalling around 1041 mm (41 in) per year. June is the wettest month and January the driest.

Grinnell Weather by Month

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

Monthly Temperature in Grinnell

In Grinnell, temperatures differ significantly between summer and winter months. Average maximum daytime temperatures range from a comfortable 29°C (84°F) in July, the warmest time of the year, to a very cold -2°C (28°F) during cooler months like January.

At night, you can expect temperatures ranging from 18°C (64°F) in July to around -12°C (10°F) during January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Rainfall in Grinnell

Grinnell experiences significant rain/snowfall throughout the year, averaging 1041 mm (41 in) of precipitation annually. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, June it receives high rainfall, averaging 158 mm (6.2 in) of precipitation, recorded across 13 rainy days. In contrast, the driest month January brings less snowfall, with 22 mm (0.9 in) over 7 snowy days. For more details, please visit our Grinnell Precipitation page.

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

Best Time to Visit Grinnell

The best time to visit Grinnell is during May, July, August and September, when the weather provides comfortable temperatures between 22°C (71°F) and 29°C (84°F). With rainfall of 96 mm (3.8 in) to 125 mm (4.9 in), you can expect pleasant weather during your visit in these months.

Looking for inspiration on where to travel this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.

Frequently asked questions about the climate in Grinnell

What is the best time to visit Grinnell?

September typically offers the most optimal weather in Grinnell. In contrast, January, February, March, November and December tend to have less optimal conditions.

What temperatures can I expect in Grinnell?

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 18°C (64°F). Temperatures vary considerably through the year.

How much rain does Grinnell get?

Annual rainfall is around 1041 mm (41 in). June is the wettest month with 158 mm (6.2 in), while January is the driest with 22 mm (0.9 in).

Grinnell 3-Day Forecast

Grinnell (IA) 3-Day Forecast

Grinnell on the map

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

Popular this month

Where to go in July — average daytime high across popular destinations.

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