Photo: Andrew Filer from Seattle (ex-Minneapolis) · CC BY-SA 2.0Few U.S. towns have colder winter nights than Shell Valley
On a normal July day the thermometer tops out near 78°. In July, afternoons here are cooler than in 96% of U.S. towns. January has warmed most since 1901–2000, part of a 1.7° rise. Garden chairs stay out from June to September, the months with highs of 68–78°.
A year in Shell Valley at a glance
Each month’s typical high and low, and what it brings.
What stands out about Shell Valley’s climate
Compared with towns across the U.S., with Shell Valley’s place in North Dakota beside it.
What a year in Shell Valley feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 126 frost-free days a year
In half of years the last 32° night comes by May 19 and the first by September 24. Frost and day counts come from NOAA’s station at Belcourt Keya Radio, ND, 4 miles from the town’s center, at about the same height.
The 2023 USDA map puts Shell Valley’s center in zone 3b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −32°. 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 19 inches of rain a year
June is the wettest month and January the driest.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Shell Valley
97% 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 Belcourt Keya Radio, ND.
Living with Shell Valley’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
126 frost-free days in zone 3b. The last frost comes by May 19 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 24.
Months with highs of 62–84° and lows of 40° or more: June, July, August and September. 18 miles of trails are waiting.
Parks & trails →Cold waves are 39% of the yearly building losses FEMA expects in Shell Valley from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Shell Valley and similar climates
TownRatings has no climate map of the towns around Shell Valley yet.
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 Shell Valley averaged 1.7° warmer than the 1900s. The biggest change is in January (+4.6°).
A bigger shift than in 70% 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 Shell Valley compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Shell Valley’s place among North Dakota’s.
Shell Valley weather by month
Highs, lows and precipitation from NOAA’s grid at Shell Valley’s center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 16° | −4° | 0.5" | −8° – 22° |
| February | 20° | 0° | 0.5" | −5° – 24° |
| March | 32° | 13° | 0.7" | 10° – 36° |
| April | 50° | 26° | 0.9" | 26° – 46° |
| May | 64° | 39° | 2.6" | 45° – 58° |
| June | 73° | 50° | 3.9" | 56° – 66° |
| July | 78° | 54° | 2.9" | 59° – 71° |
| August | 77° | 52° | 2.4" | 57° – 69° |
| September | 68° | 42° | 1.6" | 49° – 63° |
| October | 51° | 30° | 1.4" | 31° – 46° |
| November | 33° | 16° | 0.7" | 12° – 37° |
| December | 20° | 2° | 0.6" | −4° – 23° |
| Year | 48° | 27° | 18.6" |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from -8° to 22°. June is the most reliable, staying within 10°.
Where Shell Valley’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 Shell Valley’s center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Belcourt Keya Radio, ND, 4 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 Shell Valley’s climate
What is the weather like in Shell Valley?
A typical July afternoon reaches 78°, a January night drops to −4°. Colder January nights than all but 14 U.S. towns; cooler July afternoons than 96% of U.S. towns.
How cold does it get in Shell Valley in winter?
January nights average −4°. About 209 nights a year reach 32° or below and 64 reach 0° or below. In the coldest January of the last 30 years the month averaged −8°.
How hot does it get in Shell Valley?
July, with a typical high of 78° and a low of 54°. About 5 days a year reach 90° (Belcourt Keya Radio, ND).
When is the first and last frost in Shell Valley?
In half of years the last spring frost (32°) comes by May 19 and the first fall frost by September 24, about 126 frost-free days, at Belcourt Keya Radio, ND.
What growing zone is Shell Valley in?
Zone 3b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −32°.
What is the best time of year to visit Shell Valley?
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 Shell Valley getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 70% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Shell Valley.
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.