Griswold has cold winters and warm summers
A typical July afternoon reaches 85°, a January night drops to 13°, and about 27 inches of snow falls in a normal winter.
A year in Griswold at a glance
Each month’s typical high and low, and what it brings.
What stands out about Griswold’s climate
Read from where Griswold sits among Iowa’s towns. The page puts what stands out first.
About 169 frost-free days a year
In half of years the last 32° night comes by April 24 and the first by October 13.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
What a year in Griswold feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
27 inches of snow, 36 of rain and melt
June is the wettest month and January the driest. Rain or snow falls on about 102 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Living with Griswold’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
169 frost-free days. The last frost comes by Apr 24 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 13.
About 27" a winter over 9 days with an inch or more, most in February. Snow covers the ground about 44 days a year.
Months averaging under 55° run from October through April. Heating is 85% of the year’s heating-and-cooling load.
About 26 days a year reach 90°, and July afternoons average 85°.
The nicest months are May, June, August, September and October. 0.3 miles of trails are waiting.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →Warmer than it used to be
The last 30 years in Griswold averaged 0.6° warmer than the 1900s. The biggest change is in March (+2.2°).
A smaller shift than in 92% of U.S. towns.
Change by month
How Griswold compares
Against every U.S. town on TownTapestry, each counted once, with its place in Iowa.
Griswold weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 32° | 13° | 0.8" | 7.3" | 5 | 16 | 14° – 35° |
| February | 37° | 17° | 1.1" | 8.1" | 7 | 13 | 16° – 37° |
| March | 50° | 28° | 1.9" | 2.6" | 8 | 4 | 32° – 54° |
| April | 63° | 38° | 3.6" | 1.2" | 11 | 0 | 42° – 57° |
| May | 73° | 50° | 5.3" | 0 | 14 | 0 | 56° – 69° |
| June | 82° | 60° | 5.3" | 0 | 11 | 0 | 67° – 75° |
| July | 85° | 64° | 4.0" | 0 | 10 | 0 | 69° – 80° |
| August | 84° | 61° | 4.4" | 0 | 9 | 0 | 67° – 77° |
| September | 77° | 52° | 3.4" | 0 | 8 | 0 | 58° – 70° |
| October | 65° | 40° | 2.8" | 0.5" | 8 | 0 | 46° – 57° |
| November | 49° | 28° | 1.7" | 1.2" | 6 | 2 | 29° – 49° |
| December | 36° | 18° | 1.3" | 6.5" | 6 | 10 | 12° – 33° |
| Year | 61° | 39° | 35.7" | 27.4" | 102 | 44 |
Heating and cooling a home in Griswold
85% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 32° to 54°. June is the most reliable, staying within 8°.
Common questions about Griswold’s climate
What is the coldest month in Griswold?
January, with a typical high of 32° and a low of 13°.
What is the hottest month in Griswold?
July, with a typical high of 85° and a low of 64°. About 26 days a year reach 90°.
How much snow does Griswold get?
About 27 inches in a normal winter, most of it in February.
When is the first frost in Griswold?
In half of years the first 32° night comes by October 13, and the last spring frost by April 24.
What is the rainiest month in Griswold?
June, with 5.3 inches of rain and melted snow. The year totals 36 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in Griswold.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for Griswold itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Red Oak, IA (17 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000. Today’s forecast: National Weather Service.