Hardly any U.S. towns see harsher January nights than Riverside Township
July afternoons average 85°. Temperatures cover 80° across the year, low to high. Its yearly precipitation falls short of 88% of U.S. towns. Tender plants can go out after about May 12; in half of years the first frost comes by October 1.
A year in Riverside Township at a glance
Each month’s typical high and low, and what it brings.
What stands out about Riverside Township’s climate
Compared with towns across the U.S., with Riverside Township’s place in South Dakota beside it.
What a year in Riverside Township feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 142 frost-free days a year
In half of years the last 32° night comes by May 12 and the first by October 1. Frost and day counts come from NOAA’s station at Highmore 1 W, SD, 11 miles from the town’s center, 240 ft higher.
The 2023 USDA map puts Riverside Township’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −22°. 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 40 inches of snow a winter
Snow, measured at Highmore 1 W, SD, falls mostly in February. 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 58 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Riverside Township
91% 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 1 W, SD.
Living with Riverside Township’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
142 frost-free days in zone 4b. The last frost comes by May 12 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 1.
Months with highs of 62–84° and lows of 40° or more: May, June, August and September.
Parks & trails →Cold waves are 35% of the yearly building losses FEMA expects in Riverside Township from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Riverside Township and its neighbors
Every town next door is within a degree of Riverside Township in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Riverside 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 |
|---|---|---|---|---|
| Riverside Township, SD | 6° | 85° | 22" | 40" |
| Mandan, ND | 3° | 84° | 18" | 51" |
| Marshall, MN | 6° | 84° | 28" | 44" |
| Sidney, MT | 4° | 85° | 15" | 30" |
| Sioux Center, IA | 8° | 84° | 29" | 35" |
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 Riverside Township averaged 0.8° warmer than the 1900s. The biggest change is in January (+3.1°).
A smaller shift than in 88% 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 Riverside Township compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Riverside Township’s place among South Dakota’s.
Riverside Township weather by month
Highs, lows and precipitation from NOAA’s grid at Riverside Township’s center; snow, wet days and snow on the ground from Highmore 1 W, SD. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 25° | 6° | 0.5" | 6.7" | 3 | 12 | 5° – 30° |
| February | 30° | 10° | 0.7" | 9.5" | 4 | 10 | 3° – 32° |
| March | 43° | 21° | 1.0" | 5.8" | 4 | 4 | 21° – 46° |
| April | 57° | 32° | 2.2" | 4.8" | 6 | 1 | 35° – 50° |
| May | 69° | 43° | 3.6" | 0.0" | 8 | 0 | 51° – 63° |
| June | 79° | 54° | 3.8" | 0.0" | 9 | 0 | 61° – 70° |
| July | 85° | 60° | 3.0" | 0.0" | 6 | 0 | 64° – 79° |
| August | 83° | 57° | 2.4" | 0.0" | 5 | 0 | 65° – 74° |
| September | 75° | 48° | 2.1" | 0.0" | 4 | 0 | 55° – 67° |
| October | 59° | 34° | 1.8" | 1.3" | 4 | 0 | 38° – 52° |
| November | 43° | 21° | 0.6" | 5.5" | 3 | 3 | 20° – 42° |
| December | 30° | 11° | 0.5" | 6.4" | 3 | 9 | 7° – 28° |
| Year | 56° | 33° | 22.1" | 40.0" | 58 | 39 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 3° to 32°. June is the most reliable, staying within 9°.
Where Riverside 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 Riverside Township’s center.
- Snow: Highmore 1 W, SD.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Highmore 1 W, SD, 11 miles from the town’s center, 240 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 Riverside Township’s climate
What is the weather like in Riverside Township?
A typical July afternoon reaches 85°, a January night drops to 6°, and about 40 inches of snow falls in a normal winter. Colder January nights than 98% of U.S. towns; hotter July afternoons than 51% of U.S. towns.
How cold does it get in Riverside Township in winter?
January nights average 6°. About 170 nights a year reach 32° or below and 28 reach 0° or below. In the coldest January of the last 30 years the month averaged 5°.
How much snow does Riverside Township get?
About 40 inches in a normal winter at Highmore 1 W, SD, most of it in February, with snow on the ground about 39 days a year.
How hot does it get in Riverside Township?
July, with a typical high of 85° and a low of 60°. About 24 days a year reach 90° and 3 reach 100° (Highmore 1 W, SD).
When is the first and last frost in Riverside Township?
In half of years the last spring frost (32°) comes by May 12 and the first fall frost by October 1, about 142 frost-free days, at Highmore 1 W, SD.
What growing zone is Riverside Township in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −22°.
What is the best time of year to visit Riverside 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 Riverside Township getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 88% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Riverside 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.