Grinnell, IA Climate

Grinnell, IA has a temperate climate, with hot summers and cold winters. The region experiences four distinct seasons: spring, summer, fall and winter. Summers are generally humid and warm with temperatures reaching into the mid 80s Fahrenheit during the day. Winters are cold with temperatures typically in the 20s and 30s Fahrenheit during the day. Spring and autumn bring mild weather with temperatures averaging in the 50s and 60s Fahrenheit during April and October. Rainfall is spread out evenly throughout the year, although there is slightly more rain in May than other months.

Grinnell, Iowa gets 37 inches of rain, on average, per year. The US average is 38 inches of rain per year.

Grinnell averages 27 inches of snow per year. The US average is 28 inches of snow per year.

On average, there are 196 sunny days per year in Grinnell. The US average is 205 sunny days.

Grinnell gets some kind of precipitation, on average, 104 days per year. Precipitation is rain, snow, sleet, or hail that falls to the ground. In order for precipitation to be counted you have to get at least .01 inches on the ground to measure.

Weather Highlights

Summer High: the July high is around 84 degrees
Winter Low: the January low is 10
Rain: averages 37 inches of rain a year
Snow: averages 27 inches of snow a year

Bestplaces Comfort Index

The annual BestPlaces Comfort Index for Grinnell is 6.8 (10=best), which means it is about average compared to other places in Iowa.

8.8 Summer - 4.5 Winter

June, September and August are the most pleasant months in Grinnell, while January and December are the least comfortable months.

Climate	Grinnell, Iowa	United States
	36.6 in.	38.1 in.
	27.2 in.	27.8 in.
	103.8 days	106.2 days
	196 days	205 days
	83.9°	85.8°
	9.8°	21.7°
	6.8	7
	3.7	4.3
	1014 ft.	2443 ft.

Climate

YOU SHOULD KNOW

Many people confuse weather and climate but they are different. Weather is the conditions of the atmosphere over a short period of time, and climate is how the atmosphere is over long periods of time.

Weather is how the atmosphere is behaving and its effects upon life and human activities. Weather can change from minute-to-minute. Most people think of weather in terms of temperature, humidity, precipitation, cloudiness, brightness, visibility, wind, and atmospheric pressure.

Climate is the description of the long-term pattern of weather in a place. Climate can mean the average weather for a particular region and time period taken over 30 years. Climate is the average of weather over time.

July is the hottest month for Grinnell with an average high temperature of 83.9°, which ranks it as about average compared to other places in Iowa. In Grinnell, there are 5 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Grinnell are June, September and August.

In Grinnell, there are 11.8 days annually when the high temperature is over 90°, which is cooler than most places in Iowa.

January has the coldest nighttime temperatures for Grinnell with an average of 9.8°. This is about average compared to other places in Iowa.

In Grinnell, there are 151.9 days annually when the nighttime low temperature falls below freezing, which is colder than most places in Iowa.

In Grinnell, there are 18.6 days annually when the nighttime low temperature falls below zero°, which is about average compared to other places in Iowa.

The humidity is usually comfortable in Grinnell but some summer months can be sticky or muggy. July is the most humid month, though humidity is low for most of the year. The most humid months are July, August and June.

June is the wettest month in Grinnell with 5.0 inches of rain, and the driest month is January with 0.9 inches. The wettest season is Autumn with 38% of yearly precipitation and 10% occurs in Spring, which is the driest season. The annual rainfall of 36.6 inches in Grinnell means that it is wetter than most places in Iowa.

May is the rainiest month in Grinnell with 12.1 days of rain, and January is the driest month with only 6.0 rainy days. There are 103.8 rainy days annually in Grinnell, which is rainier than most places in Iowa. The rainiest season is Summer when it rains 30% of the time and the driest is Spring with only a 19% chance of a rainy day.

An annual snowfall of 27.2 inches in Grinnell means that it is less snowy than most places in Iowa. December is the snowiest month in Grinnell with 7.2 inches of snow, and 6 months of the year have significant snowfall.