Photo: Andrew Filer from Seattle (ex-Minneapolis) · CC BY-SA 2.0Coleharbor has some of the coldest winter nights among U.S. towns
Peak summer warmth arrives in July, with afternoons near 82°. It is a dry place: less rain and snow fall here than on 91% of U.S. towns. Warming shows here too: 1.3° more than in 1901–2000, led by January. The frost-free window for a garden runs roughly May 10 to September 29.
A year in Coleharbor at a glance
Each month’s typical high and low, and what it brings.
What stands out about Coleharbor’s climate
Compared with towns across the U.S., with Coleharbor’s place in North Dakota beside it.
What a year in Coleharbor feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 139 frost-free days a year
In half of years the last 32° night comes by May 10 and the first by September 29. Frost and day counts come from NOAA’s station at Underwood, ND, 7 miles from the town’s center, 140 ft higher.
The 2023 USDA map puts Coleharbor’s center in zone 4a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −25°. 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 39 inches of snow a winter
Snow, measured at Underwood, ND, falls mostly in December. Precipitation (rain plus melted snow) adds up to 17 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 89 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Coleharbor
96% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Underwood, ND.
Living with Coleharbor’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
139 frost-free days in zone 4a. The last frost comes by May 10 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 29.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September.
Parks & trails →Cold waves are 38% of the yearly building losses FEMA expects in Coleharbor from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Coleharbor and similar climates
TownRatings has no climate map of the towns around Coleharbor yet.
Climates most like Coleharbor’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 |
|---|---|---|---|---|
| Coleharbor, ND | 2° | 82° | 17" | 39" |
| Aberdeen, SD | 3° | 84° | 22" | 43" |
| Gunnison, CO | 0° | 82° | 12" | 50" |
| East Grand Forks, MN | −2° | 81° | 23" | 49" |
| Havre, MT | 6° | 85° | 13" | 41" |
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 Coleharbor averaged 1.3° warmer than the 1900s. The biggest change is in January (+4.3°).
A smaller shift than in 55% 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 Coleharbor compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Coleharbor’s place among North Dakota’s.
Coleharbor weather by month
Highs, lows and precipitation from NOAA’s grid at Coleharbor’s center; snow, wet days and snow on the ground from Underwood, ND. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 21° | 2° | 0.4" | 6.7" | 6 | 25 | −1° – 28° |
| February | 25° | 6° | 0.4" | 5.0" | 6 | 22 | −3° – 29° |
| March | 38° | 17° | 0.7" | 6.8" | 6 | 14 | 16° – 42° |
| April | 54° | 29° | 1.2" | 2.7" | 7 | 3 | 32° – 50° |
| May | 67° | 41° | 2.6" | 0.7" | 10 | 0 | 48° – 61° |
| June | 75° | 52° | 3.5" | 0.0" | 11 | 0 | 59° – 68° |
| July | 82° | 57° | 2.6" | 0.0" | 9 | 0 | 62° – 74° |
| August | 82° | 55° | 2.0" | 0.0" | 7 | 0 | 63° – 73° |
| September | 72° | 45° | 1.6" | 0.0" | 7 | 0 | 53° – 64° |
| October | 55° | 33° | 1.3" | 1.6" | 7 | 1 | 36° – 49° |
| November | 38° | 19° | 0.6" | 4.2" | 5 | 5 | 16° – 40° |
| December | 25° | 8° | 0.6" | 10.9" | 7 | 17 | 5° – 27° |
| Year | 53° | 30° | 17.4" | 38.6" | 89 | 87 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from -3° to 29°. June is the most reliable, staying within 9°.
Where Coleharbor’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 Coleharbor’s center.
- Snow: Underwood, ND.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Underwood, ND, 7 miles from the town’s center, 140 ft higher; 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 Coleharbor’s climate
What is the weather like in Coleharbor?
A typical July afternoon reaches 82°, a January night drops to 2°, and about 39 inches of snow falls in a normal winter. Colder January nights than all but 85 U.S. towns; cooler July afternoons than 81% of U.S. towns.
How cold does it get in Coleharbor in winter?
January nights average 2°. About 186 nights a year reach 32° or below and 41 reach 0° or below. In the coldest January of the last 30 years the month averaged −1°.
How much snow does Coleharbor get?
About 39 inches in a normal winter at Underwood, ND, most of it in December, with snow on the ground about 87 days a year.
How hot does it get in Coleharbor?
July, with a typical high of 82° and a low of 57°. About 16 days a year reach 90° (Underwood, ND).
When is the first and last frost in Coleharbor?
In half of years the last spring frost (32°) comes by May 10 and the first fall frost by September 29, about 139 frost-free days, at Underwood, ND.
What growing zone is Coleharbor in?
Zone 4a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −25°.
What is the best time of year to visit Coleharbor?
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 Coleharbor getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 55% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Coleharbor.
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.