Photo: Don Graham on Flickr · CC BY-SA 2.0Hardly any U.S. towns see harsher January nights than Doon
Peak summer warmth arrives in July, with afternoons near 84°. It is a dry place: less rain and snow fall here than on 86% of U.S. towns. The latest 30-year average runs 0.9° warmer than 1901–2000’s, with January up the most. Tender plants can go out after about May 1; in half of years the first frost comes by October 4.
A year in Doon at a glance
Each month’s typical high and low, and what it brings.
What stands out about Doon’s climate
Compared with towns across the U.S., with Doon’s place in Iowa beside it.
What a year in Doon feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 156 frost-free days a year
In half of years the last 32° night comes by May 1 and the first by October 4. Frost and day counts come from NOAA’s station at Rock Rapids, IA, 11 miles from the town’s center, at about the same height.
The 2023 USDA map puts Doon’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −19°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 34 inches of snow a winter
Snow, measured at Rock Valley, IA, falls mostly in December. Precipitation (rain plus melted snow) adds up to 29 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 87 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Doon
91% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Rock Rapids, IA.
Living with Doon’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
156 frost-free days in zone 5a. The last frost comes by May 1 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 4.
Months with highs of 62–84° and lows of 40° or more: May, June, August and September. 0.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Doon from natural hazards, river flooding is the largest share (29%); heat waves, cold waves, winter storms and ice storms together are 17%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Doon and similar climates
TownRatings has no climate map of the towns around Doon yet.
Climates most like Doon’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Doon, IA | 7° | 84° | 29" | 34" |
| Belle Plaine, MN | 6° | 83° | 33" | 40" |
| Berlin, WI | 9° | 82° | 33" | 38" |
| Aberdeen, SD | 3° | 84° | 22" | 43" |
| Roscoe, IL | 13° | 84° | 37" | 38" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Doon averaged 0.9° warmer than the 1900s. The biggest change is in January (+2.3°).
A smaller shift than in 86% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Doon compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Doon’s place among Iowa’s.
Doon weather by month
Highs, lows and precipitation from NOAA’s grid at Doon’s center; snow, wet days and snow on the ground from Rock Valley, IA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 26° | 7° | 0.6" | 6.7" | 5 | 6° – 31° |
| February | 31° | 12° | 0.8" | 7.3" | 4 | 10° – 33° |
| March | 44° | 24° | 1.5" | 4.7" | 6 | 25° – 50° |
| April | 59° | 35° | 3.0" | 2.8" | 9 | 36° – 54° |
| May | 71° | 47° | 4.1" | 0.1" | 12 | 53° – 65° |
| June | 81° | 58° | 4.7" | 0.0" | 11 | 65° – 74° |
| July | 84° | 62° | 3.3" | 0.0" | 8 | 66° – 79° |
| August | 82° | 59° | 3.2" | 0.0" | 8 | 65° – 74° |
| September | 75° | 50° | 3.2" | 0.0" | 8 | 56° – 67° |
| October | 61° | 37° | 2.4" | 0.5" | 7 | 42° – 54° |
| November | 44° | 24° | 1.3" | 3.7" | 5 | 24° – 45° |
| December | 30° | 13° | 0.9" | 8.5" | 5 | 8° – 28° |
| Year | 57° | 35° | 29.0" | 34.3" | 87 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 6° to 31°. June is the most reliable, staying within 9°.
Where Doon’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Doon’s center.
- Snow: Rock Valley, IA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Rock Rapids, IA, 11 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Doon’s climate
What is the weather like in Doon?
A typical July afternoon reaches 84°, a January night drops to 7°, and about 34 inches of snow falls in a normal winter. Colder January nights than 96% of U.S. towns; cooler July afternoons than 57% of U.S. towns.
How cold does it get in Doon in winter?
January nights average 7°. About 169 nights a year reach 32° or below and 28 reach 0° or below. In the coldest January of the last 30 years the month averaged 6°.
How much snow does Doon get?
About 34 inches in a normal winter at Rock Valley, IA, most of it in December.
How hot does it get in Doon?
July, with a typical high of 84° and a low of 62°. About 19 days a year reach 90° (Rock Rapids, IA).
When is the first and last frost in Doon?
In half of years the last spring frost (32°) comes by May 1 and the first fall frost by October 4, about 156 frost-free days, at Rock Rapids, IA.
What growing zone is Doon in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −19°.
What is the best time of year to visit Doon?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Doon getting warmer?
Yes: 1991–2020 averaged 0.9° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 86% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Doon.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.