Ontario Township’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 85°, a January night drops to 6°, and about 44 inches of snow falls in a normal winter.
A year in Ontario Township at a glance
Each month’s typical high and low, and what it brings.
What stands out about Ontario Township’s climate
Compared with towns across the U.S., with Ontario Township’s place in South Dakota beside it.
What a year in Ontario Township feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 138 frost-free days a year
In half of years the last 32° night comes by May 14 and the first by September 29. Frost and day counts come from NOAA’s station at Highmore 23 N, SD, 13 miles from the town’s center, 170 ft higher.
The 2023 USDA map puts Ontario Township’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −23°. 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 Faulkton 1 Nw, SD, falls mostly in February and 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 88 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Ontario Township
94% 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 Highmore 23 N, SD.
Living with Ontario Township’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
138 frost-free days in zone 4b. The last frost comes by May 14 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, August and September. 3.8 miles of trails are waiting.
Parks & trails →Cold waves are 35% of the yearly building losses FEMA expects in Ontario Township from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Ontario Township and its neighbors
Every town next door is within a degree of Ontario Township in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Ontario Township’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 |
|---|---|---|---|---|
| Ontario Township, SD | 6° | 85° | 22" | 44" |
| Mandan, ND | 3° | 84° | 18" | 51" |
| Montevideo, MN | 4° | 83° | 28" | 46" |
| Sidney, MT | 4° | 85° | 15" | 30" |
| 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 Ontario Township averaged 0.9° warmer than the 1900s. The biggest change is in January (+3.2°).
A smaller shift than in 87% 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 Ontario Township compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Ontario Township’s place among South Dakota’s.
Ontario Township weather by month
Highs, lows and precipitation from NOAA’s grid at Ontario Township’s center; snow, wet days and snow on the ground from Faulkton 1 Nw, SD. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 24° | 6° | 0.5" | 7.6" | 6 | 5° – 30° |
| February | 29° | 9° | 0.6" | 9.3" | 5 | 2° – 31° |
| March | 42° | 21° | 0.9" | 6.8" | 5 | 21° – 46° |
| April | 56° | 31° | 2.0" | 7.1" | 8 | 34° – 50° |
| May | 68° | 43° | 3.4" | 0.0" | 11 | 50° – 63° |
| June | 78° | 54° | 3.6" | 0.0" | 12 | 61° – 70° |
| July | 85° | 59° | 3.0" | 0.0" | 9 | 63° – 79° |
| August | 83° | 57° | 2.5" | 0.0" | 8 | 65° – 74° |
| September | 74° | 47° | 2.0" | 0.0" | 8 | 55° – 66° |
| October | 59° | 34° | 1.8" | 0.9" | 7 | 38° – 52° |
| November | 42° | 21° | 0.6" | 3.4" | 5 | 20° – 41° |
| December | 29° | 10° | 0.5" | 8.6" | 5 | 6° – 28° |
| Year | 56° | 33° | 21.5" | 43.7" | 88 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 2° to 31°. August is the most reliable, staying within 9°.
Where Ontario Township’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 Ontario Township’s center.
- Snow: Faulkton 1 Nw, SD.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Highmore 23 N, SD, 13 miles from the town’s center, 170 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 Ontario Township’s climate
What is the weather like in Ontario Township?
A typical July afternoon reaches 85°, a January night drops to 6°, and about 44 inches of snow falls in a normal winter. Colder January nights than 98% of U.S. towns; cooler July afternoons than 54% of U.S. towns.
How cold does it get in Ontario Township in winter?
January nights average 6°. About 177 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 5°.
How much snow does Ontario Township get?
About 44 inches in a normal winter at Faulkton 1 Nw, SD, most of it in February and December.
How hot does it get in Ontario Township?
July, with a typical high of 85° and a low of 59°. About 25 days a year reach 90° and 3 reach 100° (Highmore 23 N, SD).
When is the first and last frost in Ontario Township?
In half of years the last spring frost (32°) comes by May 14 and the first fall frost by September 29, about 138 frost-free days, at Highmore 23 N, SD.
What growing zone is Ontario Township in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −23°.
What is the best time of year to visit Ontario Township?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Ontario Township getting warmer?
Yes: 1991–2020 averaged 0.9° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 87% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Ontario Township.
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.