Photo: Andrew Filer · CC BY-SA 2.0South Heart has some of the coldest winter nights among U.S. towns
On a normal July day the thermometer tops out near 84°. Rain follows the seasons: June brings about 8.6 times as much as January. It is a dry place: less rain and snow fall here than on 92% of U.S. towns. For walks and days out, the stretch from June to September brings highs of 73–84°.
A year in South Heart at a glance
Each month’s typical high and low, and what it brings.
What stands out about South Heart’s climate
Compared with towns across the U.S., with South Heart’s place in North Dakota beside it.
What a year in South Heart feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 129 frost-free days a year
In half of years the last 32° night comes by May 18 and the first by September 25. Frost and day counts come from NOAA’s station at Theodore Roosevelt Airport, 10 miles from the town’s center, at about the same height.
The 2023 USDA map puts South Heart’s center in zone 4a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −26°. 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 44 inches of snow a winter
Snow, measured at Dickinson Rch Hq, ND, falls mostly in February, March and December. Precipitation (rain plus melted snow) adds up to 16 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 69 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in South Heart
95% 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 Theodore Roosevelt Airport.
Living with South Heart’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
129 frost-free days in zone 4a. The last frost comes by May 18 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 25.
Months with highs of 62–84° and lows of 40° or more: June, July, August and September. 3.2 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in South Heart from natural hazards, river flooding is the largest share (35%); heat waves, cold waves, winter storms and ice storms together are 37%. Normals are averages; the hazards page covers the extremes.
Natural hazards →South Heart and similar climates
TownRatings has no climate map of the towns around South Heart yet.
Climates most like South Heart’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 |
|---|---|---|---|---|
| South Heart, ND | 5° | 84° | 16" | 44" |
| Havre, MT | 6° | 85° | 13" | 41" |
| Aberdeen, SD | 3° | 84° | 22" | 43" |
| Gunnison, CO | 0° | 82° | 12" | 50" |
| Taos, NM | 11° | 84° | 13" | 28" |
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 South Heart averaged 1.1° warmer than the 1900s. The biggest change is in January (+4.2°).
A smaller shift than in 67% 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 South Heart compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with South Heart’s place among North Dakota’s.
South Heart weather by month
Highs, lows and precipitation from NOAA’s grid at South Heart’s center; snow, wet days and snow on the ground from Dickinson Rch Hq, ND. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 26° | 5° | 0.3" | 6.0" | 5 | 5° – 29° |
| February | 30° | 8° | 0.4" | 8.0" | 5 | −1° – 31° |
| March | 42° | 19° | 0.6" | 7.8" | 5 | 17° – 44° |
| April | 55° | 29° | 1.3" | 4.1" | 5 | 35° – 48° |
| May | 66° | 40° | 2.6" | 1.4" | 9 | 48° – 59° |
| June | 76° | 50° | 2.9" | 0.0" | 9 | 58° – 67° |
| July | 84° | 55° | 2.3" | 0.0" | 7 | 61° – 75° |
| August | 84° | 53° | 1.7" | 0.0" | 6 | 63° – 73° |
| September | 73° | 43° | 1.6" | 0.0" | 6 | 52° – 63° |
| October | 56° | 30° | 1.2" | 3.7" | 5 | 34° – 49° |
| November | 41° | 19° | 0.5" | 4.7" | 4 | 17° – 40° |
| December | 30° | 9° | 0.3" | 8.3" | 4 | 7° – 27° |
| Year | 55° | 30° | 15.7" | 44.0" | 69 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from -1° to 31°. June is the most reliable, staying within 9°.
Where South Heart’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 South Heart’s center.
- Snow: Dickinson Rch Hq, ND.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Theodore Roosevelt Airport, 10 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 South Heart’s climate
What is the weather like in South Heart?
A typical July afternoon reaches 84°, a January night drops to 5°, and about 44 inches of snow falls in a normal winter. Colder January nights than all but 181 U.S. towns; cooler July afternoons than 63% of U.S. towns.
How cold does it get in South Heart in winter?
January nights average 5°. About 189 nights a year reach 32° or below and 32 reach 0° or below. In the coldest January of the last 30 years the month averaged 5°.
How much snow does South Heart get?
About 44 inches in a normal winter at Dickinson Rch Hq, ND, most of it in February, March and December.
How hot does it get in South Heart?
July, with a typical high of 84° and a low of 55°. About 20 days a year reach 90° and 2 reach 100° (Theodore Roosevelt Airport).
When is the first and last frost in South Heart?
In half of years the last spring frost (32°) comes by May 18 and the first fall frost by September 25, about 129 frost-free days, at Theodore Roosevelt Airport.
What growing zone is South Heart in?
Zone 4a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −26°.
What is the best time of year to visit South Heart?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is South Heart getting warmer?
Yes: 1991–2020 averaged 1.1° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 67% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in South Heart.
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.