The Grimes almanac: the town by the numbers, in one place.
The quick answer
Population17,809 (2025 special census), 15,392 in 2020
PlacePolk + Dallas counties, ZIP 50111, area code 515
FoundedPlatted 1881, incorporated 1894, named for Gov. James W. Grimes
WeatherJuly high 86°, January high 31°, about 36.5 in. of snow a year
FrostMedian last spring freeze April 18, first fall freeze October 20
People
Population and growth
2010 Census8,246
2020 Census15,392
Growth 2010 to 2020+86.7%
2025 special census17,809
Money and housing
Income and homes
Median household income~$120,037
Median home value~$304,700
Homeownership rate~70.9%
Place
Geography and government
CountiesPolk + Dallas
ZIP code50111
Area code515
School districtDallas Center-Grimes
City websitegrimesiowa.gov
History
Founding
Platted1881
Incorporated1894
Named forGov. James W. Grimes
Named for James W. Grimes, the third Governor of Iowa and later a U.S. Senator, which is also where the June Governor's Days festival gets its name. More in our history guide.
Local anchors
Good to know
Schools: Dallas Center-Grimes, home of the Mustangs, Little Hawkeye Conference.
Golf: Beaver Creek Golf Course, public, 27 holes.
Market: Grimes Farmers and Community Market, Saturdays at Heritage Park in season.
Festival: Governor's Days, first weekend of June.
Weather
What is the weather like in Grimes by month?
Warm, wet summers and cold, snowy winters. These are NOAA's 1991 to 2020 climate normals for Des Moines International Airport, about 17 miles from Grimes by car: average high / average low, then average precipitation (rain plus melted snow).
January30.9° / 13.8° · 1.08 in.
February35.7° / 18.0° · 1.34 in.
March49.2° / 29.6° · 2.17 in.
April62.0° / 40.6° · 4.02 in.
May72.4° / 52.3° · 5.24 in.
June81.9° / 62.4° · 5.26 in.
July85.6° / 66.4° · 3.82 in.
August83.6° / 64.2° · 4.17 in.
September76.9° / 55.4° · 3.18 in.
October63.4° / 42.9° · 2.78 in.
November48.3° / 30.2° · 1.91 in.
December35.9° / 19.5° · 1.58 in.
May and June are the wettest months, each above 5 inches. Normal snowfall peaks in February (10.2 in.), January (9.4) and December (7.9).
How much snow, heat and cold does Grimes get in a year?
Average temperature50.9°F
Precipitation36.55 in.
Snowfall36.5 in.
Days with 1 in.+ of snowabout 11
Days at 90° or hotterabout 22
Nights at 32° or colderabout 128
When is the first frost in Grimes?
Half the time, the first fall freeze (32°) has come by October 20, and the last spring freeze is over by April 18, for a median growing season of 184 days. Gardeners, plan for the edges: there's a 1 in 10 chance of a freeze on or after May 2, and a 1 in 10 chance the first fall freeze arrives by October 4. The median first hard freeze (28°) is October 30.
Sky
What time does the sun rise and set in Grimes?
From the U.S. Naval Observatory's calculator for Grimes:
Longest day, June 21, 20265:41 a.m. / 8:53 p.m.
Shortest day, Dec. 21, 20267:39 a.m. / 4:48 p.m.
Earliest sunset, early Dec.4:45 p.m.
Latest sunrise, early Jan. 20277:42 a.m.
That is about 15 hours 12 minutes of daylight at midsummer and 9 hours 9 minutes at the winter solstice.
Records
What are the weather records for the Grimes area?
From the National Weather Service Des Moines office's climate record for Des Moines, kept since 1878:
Record high110° (July 25, 1936, and Aug. 4, 1918)
Record low−30° (Jan. 5, 1884)
Wettest day6.18 in. (Aug. 27, 1975)
Snowiest day19.8 in. (Jan. 1, 1942)
Snowiest season72.0 in. (1911 to 1912)
Driest year17.07 in. (1956)
One from this year: the earliest 90-degree day on record in Des Moines was March 21, 2026.
FAQ
Grimes almanac: FAQ
What is the population of Grimes, Iowa?
A 2025 special census counted about 17,809 residents, up from 15,392 in the 2020 Census and 8,246 in 2010, one of the fastest growth rates in the state.
What county and ZIP code is Grimes, Iowa?
Grimes uses ZIP code 50111 and is split between Polk County (most of the city) and Dallas County (the west side).
When is the first frost in Grimes, Iowa?
Based on NOAA's 1991 to 2020 normals for Des Moines, the median first fall freeze is October 20 and the median last spring freeze is April 18. There is about a 1 in 10 chance of a spring freeze on or after May 2.
How much snow does Grimes, Iowa get?
About 36.5 inches a year on average, per NOAA's 1991 to 2020 normals for Des Moines. February is the snowiest month at 10.2 inches, followed by January at 9.4.
The town, tracked weekly
The Grimes Brief keeps these numbers current and tells you what is changing. Free every Monday.