Hardly any U.S. towns see harsher January nights than Ferney
July afternoons average 83°. The gap between a January night and a July afternoon is 81°. It is a dry place: less rain and snow fall here than on 89% of U.S. towns. The frost-free window for a garden runs roughly May 6 to October 4.
A year in Ferney at a glance
Each month’s typical high and low, and what it brings.
What stands out about Ferney’s climate
Compared with towns across the U.S., with Ferney’s place in South Dakota beside it.
What a year in Ferney feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 150 frost-free days a year
In half of years the last 32° night comes by May 6 and the first by October 4. Frost and day counts come from NOAA’s station at Andover #2, SD, 11 miles from the town’s center, 180 ft higher.
The 2023 USDA map puts Ferney’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 32 inches of snow a winter
Snow, measured at Groton, SD, falls mostly in December. Precipitation (rain plus melted snow) adds up to 22 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 71 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Ferney
93% 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 Andover #2, SD.
Living with Ferney’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
150 frost-free days in zone 4a. The last frost comes by May 6 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, July, August and September.
Parks & trails →Of the yearly building losses FEMA expects in Ferney from natural hazards, river flooding is the largest share (39%); heat waves, cold waves, winter storms and ice storms together are 39%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Ferney and its neighbors
Every town next door is within a degree of Ferney in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Ferney’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 |
|---|---|---|---|---|
| Ferney, SD | 3° | 83° | 22" | 32" |
| Dickinson, ND | 5° | 83° | 16" | 35" |
| Sidney, MT | 4° | 85° | 15" | 30" |
| Litchfield, MN | 4° | 82° | 28" | 41" |
| Sheldon, IA | 7° | 84° | 30" | 41" |
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 Ferney averaged 1.3° warmer than the 1900s. The biggest change is in January (+3.4°).
A smaller shift than in 57% 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 Ferney compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Ferney’s place among South Dakota’s.
Ferney weather by month
Highs, lows and precipitation from NOAA’s grid at Ferney’s center; snow, wet days and snow on the ground from Groton, SD. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 22° | 3° | 0.5" | 4.7" | 5 | −1° – 26° |
| February | 27° | 7° | 0.6" | 5.8" | 5 | 2° – 29° |
| March | 40° | 20° | 0.9" | 6.7" | 5 | 19° – 44° |
| April | 56° | 32° | 1.9" | 4.5" | 6 | 34° – 51° |
| May | 69° | 45° | 3.0" | 0.0" | 8 | 52° – 64° |
| June | 79° | 56° | 3.7" | 0.0" | 9 | 62° – 72° |
| July | 83° | 60° | 3.4" | 0.0" | 6 | 64° – 77° |
| August | 82° | 58° | 2.3" | 0.0" | 6 | 64° – 74° |
| September | 73° | 48° | 2.2" | 0.0" | 7 | 54° – 65° |
| October | 58° | 35° | 2.0" | 0.5" | 5 | 39° – 51° |
| November | 41° | 21° | 0.7" | 2.0" | 4 | 18° – 42° |
| December | 27° | 9° | 0.6" | 8.1" | 6 | 4° – 26° |
| Year | 55° | 33° | 21.8" | 32.3" | 71 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from -1° to 26°. August is the most reliable, staying within 10°.
Where Ferney’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 Ferney’s center.
- Snow: Groton, SD.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Andover #2, SD, 11 miles from the town’s center, 180 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 Ferney’s climate
What is the weather like in Ferney?
A typical July afternoon reaches 83°, a January night drops to 3°, and about 32 inches of snow falls in a normal winter. Colder January nights than all but 88 U.S. towns; cooler July afternoons than 66% of U.S. towns.
How cold does it get in Ferney in winter?
January nights average 3°. About 165 nights a year reach 32° or below and 33 reach 0° or below. In the coldest January of the last 30 years the month averaged −1°.
How much snow does Ferney get?
About 32 inches in a normal winter at Groton, SD, most of it in December.
How hot does it get in Ferney?
July, with a typical high of 83° and a low of 60°. About 11 days a year reach 90° (Andover #2, SD).
When is the first and last frost in Ferney?
In half of years the last spring frost (32°) comes by May 6 and the first fall frost by October 4, about 150 frost-free days, at Andover #2, SD.
What growing zone is Ferney 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 Ferney?
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 Ferney getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 57% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Ferney.
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.