Few U.S. towns have colder winter nights than Oldham
Expect July afternoons of about 83°. A year here swings 78° from midwinter lows to midsummer highs. Precipitation is light here, less than falls on 87% of U.S. towns. Keep the boiler serviced for the months from October to April, which average under 50°.
A year in Oldham at a glance
Each month’s typical high and low, and what it brings.
What stands out about Oldham’s climate
Compared with towns across the U.S., with Oldham’s place in South Dakota beside it.
What a year in Oldham feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 151 frost-free days a year
In half of years the last 32° night comes by May 3 and the first by October 2. Frost and day counts come from NOAA’s station at Arlington 1 W, SD, 12 miles from the town’s center, 100 ft higher.
The 2023 USDA map puts Oldham’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −21°. 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 De Smet, SD, falls mostly in February. Precipitation (rain plus melted snow) adds up to 26 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 74 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Oldham
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 Arlington 1 W, SD.
Living with Oldham’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
151 frost-free days in zone 4b. The last frost comes by May 3 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 2.
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 Oldham from natural hazards, river flooding is the largest share (33%); heat waves, cold waves, winter storms and ice storms together are 33%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Oldham and its neighbors
Every town next door is within a degree of Oldham in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Oldham’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 |
|---|---|---|---|---|
| Oldham, SD | 5° | 83° | 26" | 41" |
| Litchfield, MN | 4° | 82° | 28" | 41" |
| West Fargo, ND | 0° | 82° | 24" | 51" |
| Storm Lake, IA | 9° | 83° | 31" | 31" |
| Hudson, WI | 6° | 82° | 33" | 50" |
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 Oldham averaged 0.8° warmer than the 1900s. The biggest change is in January (+2.8°).
A smaller shift than in 89% 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 Oldham compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Oldham’s place among South Dakota’s.
Oldham weather by month
Highs, lows and precipitation from NOAA’s grid at Oldham’s center; snow, wet days and snow on the ground from De Smet, SD. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 24° | 5° | 0.6" | 6.2" | 4 | 27 | 2° – 28° |
| February | 29° | 9° | 0.7" | 9.2" | 4 | 21 | 5° – 31° |
| March | 41° | 21° | 1.3" | 6.9" | 5 | 13 | 20° – 46° |
| April | 56° | 33° | 2.5" | 4.8" | 7 | 3 | 35° – 51° |
| May | 68° | 45° | 3.5" | 0.0" | 10 | 0 | 52° – 64° |
| June | 78° | 56° | 4.0" | 0.0" | 10 | 0 | 61° – 71° |
| July | 83° | 60° | 3.4" | 0.0" | 8 | 0 | 63° – 78° |
| August | 80° | 58° | 3.2" | 0.0" | 7 | 0 | 64° – 73° |
| September | 73° | 49° | 2.8" | 0.0" | 6 | 0 | 54° – 66° |
| October | 58° | 35° | 2.2" | 1.6" | 6 | 1 | 39° – 51° |
| November | 42° | 22° | 1.0" | 5.4" | 4 | 6 | 21° – 42° |
| December | 28° | 10° | 0.7" | 7.3" | 4 | 20 | 5° – 26° |
| Year | 55° | 34° | 25.9" | 41.4" | 74 | 91 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 20° to 46°. August is the most reliable, staying within 9°.
Where Oldham’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 Oldham’s center.
- Snow: De Smet, SD.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Arlington 1 W, SD, 12 miles from the town’s center, 100 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 Oldham’s climate
What is the weather like in Oldham?
A typical July afternoon reaches 83°, a January night drops to 5°, and about 41 inches of snow falls in a normal winter. Colder January nights than 98% of U.S. towns; cooler July afternoons than 76% of U.S. towns.
How cold does it get in Oldham in winter?
January nights average 5°. About 166 nights a year reach 32° or below and 30 reach 0° or below. In the coldest January of the last 30 years the month averaged 2°.
How much snow does Oldham get?
About 41 inches in a normal winter at De Smet, SD, most of it in February, with snow on the ground about 91 days a year.
How hot does it get in Oldham?
July, with a typical high of 83° and a low of 60°. About 10 days a year reach 90° (Arlington 1 W, SD).
When is the first and last frost in Oldham?
In half of years the last spring frost (32°) comes by May 3 and the first fall frost by October 2, about 151 frost-free days, at Arlington 1 W, SD.
What growing zone is Oldham in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −21°.
What is the best time of year to visit Oldham?
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 Oldham getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 89% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Oldham.
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.