Photo: McGhiever · CC BY-SA 3.0Cottage Grove has some of the coldest winter nights among U.S. towns
Midsummer highs settle at about 82°. Winter and summer sit 75° apart. By precipitation alone, it ranks drier than 81% of U.S. towns. Central heating does most of its work from October to April, in months below 50° on average.
A year in Cottage Grove at a glance
Each month’s typical high and low, and what it brings.
What stands out about Cottage Grove’s climate
Compared with towns across the U.S., with Cottage Grove’s place in Minnesota beside it.
What a year in Cottage Grove feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 177 frost-free days a year
In half of years the last 32° night comes by April 23 and the first by October 19. Frost and day counts come from NOAA’s station at Hastings Dam 2, MN, 4 miles from the town’s center, 170 ft lower.
The 2023 USDA map puts Cottage Grove’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −18°. 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 41 inches of snow a winter
Snow, measured at Farmington 3 Nw, MN, falls mostly in January. Precipitation (rain plus melted snow) adds up to 33 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 94 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Cottage Grove
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 Hastings Dam 2, MN.
Living with Cottage Grove’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
177 frost-free days in zone 5a. The last frost comes by Apr 23 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 19.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 17 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Cottage Grove from natural hazards, river flooding is the largest share (36%); heat waves, cold waves, winter storms and ice storms together are 18%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Cottage Grove and its neighbors
Every town next door is within a degree of Cottage Grove in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Cottage Grove’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 |
|---|---|---|---|---|
| Cottage Grove, MN | 7° | 82° | 33" | 41" |
| Saratoga, WI | 7° | 82° | 34" | 48" |
| Fort Dodge, IA | 9° | 83° | 34" | 39" |
| Plattsburgh, NY | 9° | 81° | 35" | 50" |
| Harrisburg, SD | 8° | 84° | 29" | 49" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Cottage Grove averaged 1.4° warmer than the 1900s. The biggest change is in January (+3.4°).
A bigger shift than in 53% 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 Cottage Grove compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Cottage Grove’s place among Minnesota’s.
Cottage Grove weather by month
Highs, lows and precipitation from NOAA’s grid at Cottage Grove’s center; snow, wet days and snow on the ground from Farmington 3 Nw, MN. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 23° | 7° | 0.9" | 10.5" | 6 | 4° – 28° |
| February | 28° | 11° | 0.8" | 6.4" | 5 | 7° – 32° |
| March | 41° | 23° | 1.7" | 8.0" | 6 | 23° – 48° |
| April | 56° | 36° | 3.0" | 1.8" | 8 | 35° – 54° |
| May | 69° | 48° | 4.2" | 0.0" | 11 | 53° – 66° |
| June | 78° | 58° | 5.0" | 0.0" | 11 | 64° – 72° |
| July | 82° | 63° | 4.2" | 0.0" | 10 | 65° – 78° |
| August | 80° | 61° | 4.5" | 0.0" | 9 | 65° – 75° |
| September | 72° | 53° | 3.4" | 0.0" | 8 | 55° – 67° |
| October | 58° | 39° | 2.7" | 0.3" | 7 | 42° – 54° |
| November | 42° | 26° | 1.6" | 7.0" | 6 | 24° – 46° |
| December | 28° | 14° | 1.2" | 7.0" | 6 | 8° – 30° |
| Year | 55° | 36° | 33.3" | 41.0" | 94 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 23° to 48°. June is the most reliable, staying within 8°.
Where Cottage Grove’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 Cottage Grove’s center.
- Snow: Farmington 3 Nw, MN.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Hastings Dam 2, MN, 4 miles from the town’s center, 170 ft lower; 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 Cottage Grove’s climate
What is the weather like in Cottage Grove?
A typical July afternoon reaches 82°, a January night drops to 7°, and about 41 inches of snow falls in a normal winter. Colder January nights than 96% of U.S. towns; cooler July afternoons than 79% of U.S. towns.
How cold does it get in Cottage Grove in winter?
January nights average 7°. About 150 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 4°.
How much snow does Cottage Grove get?
About 41 inches in a normal winter at Farmington 3 Nw, MN, most of it in January.
How hot does it get in Cottage Grove?
July, with a typical high of 82° and a low of 63°. About 8 days a year reach 90° (Hastings Dam 2, MN).
When is the first and last frost in Cottage Grove?
In half of years the last spring frost (32°) comes by April 23 and the first fall frost by October 19, about 177 frost-free days, at Hastings Dam 2, MN.
What growing zone is Cottage Grove in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −18°.
What is the best time of year to visit Cottage Grove?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Cottage Grove getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 53% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Cottage Grove.
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.