Merton Township’s winters are colder than most of the U.S.; July afternoons average 82°
A typical July afternoon reaches 82°, a January night drops to 4°.
A year in Merton Township at a glance
Each month’s typical high and low, and what it brings.
What stands out about Merton Township’s climate
Compared with towns across the U.S., with Merton Township’s place in South Dakota beside it.
What a year in Merton Township feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 153 frost-free days a year
In half of years the last 32° night comes by May 5 and the first by October 5. Frost and day counts come from NOAA’s station at Clark, SD, 9 miles from the town’s center, at about the same height.
The 2023 USDA map puts Merton 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 25 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 Merton 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 Clark, SD.
Living with Merton Township’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
153 frost-free days in zone 4b. The last frost comes by May 5 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 5.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 6.9 miles of trails are waiting.
Parks & trails →Cold waves are 42% of the yearly building losses FEMA expects in Merton Township from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Merton Township and its neighbors
Every town next door is within a degree of Merton Township in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
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 Merton Township averaged 1.2° warmer than the 1900s. The biggest change is in January (+3.1°).
A smaller shift than in 63% 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 Merton Township compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Merton Township’s place among South Dakota’s.
Merton Township weather by month
Highs, lows and precipitation from NOAA’s grid at Merton Township’s center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 22° | 4° | 0.6" | 1° – 26° |
| February | 27° | 8° | 0.7" | 4° – 29° |
| March | 40° | 20° | 1.1" | 19° – 44° |
| April | 55° | 32° | 2.2" | 34° – 51° |
| May | 67° | 44° | 3.2" | 51° – 63° |
| June | 77° | 55° | 4.1" | 61° – 70° |
| July | 82° | 60° | 3.5" | 62° – 78° |
| August | 80° | 58° | 2.9" | 63° – 73° |
| September | 72° | 48° | 2.6" | 53° – 66° |
| October | 57° | 35° | 2.2" | 38° – 51° |
| November | 40° | 21° | 0.8" | 20° – 42° |
| December | 27° | 10° | 0.7" | 5° – 25° |
| Year | 54° | 33° | 24.6" |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 4° to 29°. June is the most reliable, staying within 10°.
Where Merton 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 Merton Township’s center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Clark, SD, 9 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 Merton Township’s climate
What is the weather like in Merton Township?
A typical July afternoon reaches 82°, a January night drops to 4°. Colder January nights than all but 137 U.S. towns; cooler July afternoons than 81% of U.S. towns.
How cold does it get in Merton Township in winter?
January nights average 4°. About 172 nights a year reach 32° or below and 35 reach 0° or below. In the coldest January of the last 30 years the month averaged 1°.
How hot does it get in Merton Township?
July, with a typical high of 82° and a low of 60°. About 9 days a year reach 90° (Clark, SD).
When is the first and last frost in Merton Township?
In half of years the last spring frost (32°) comes by May 5 and the first fall frost by October 5, about 153 frost-free days, at Clark, SD.
What growing zone is Merton 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 Merton Township?
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 Merton Township getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 63% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Merton 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.