Hardly any U.S. towns see harsher January nights than Cortlandt Township
July afternoons average 83°. By precipitation alone, it ranks drier than 89% of U.S. towns. Since 1901–2000, the year has warmed by 0.8°, most of all in January. Warm coats and heating bills mark the months from October to April, when means dip under 50°.
A year in Cortlandt Township at a glance
Each month’s typical high and low, and what it brings.
What stands out about Cortlandt Township’s climate
Compared with towns across the U.S., with Cortlandt Township’s place in South Dakota beside it.
What a year in Cortlandt Township feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 143 frost-free days a year
In half of years the last 32° night comes by May 8 and the first by September 29. Frost and day counts come from NOAA’s station at Ipswich, SD, 13 miles from the town’s center, at about the same height.
The 2023 USDA map puts Cortlandt Township’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −24°. 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 34 inches of snow a winter
Snow, measured at Ipswich, SD, falls mostly in February. Precipitation (rain plus melted snow) adds up to 21 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 64 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Cortlandt 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 Ipswich, SD.
Living with Cortlandt Township’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
143 frost-free days in zone 4b. The last frost comes by May 8 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, July, August and September. 12 miles of trails are waiting.
Parks & trails →Cold waves are 35% of the yearly building losses FEMA expects in Cortlandt Township from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Cortlandt Township and its neighbors
Every town next door is within a degree of Cortlandt Township in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Cortlandt 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 |
|---|---|---|---|---|
| Cortlandt Township, SD | 3° | 83° | 21" | 34" |
| Dickinson, ND | 5° | 83° | 16" | 35" |
| Montevideo, MN | 4° | 83° | 28" | 46" |
| 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 Cortlandt Township averaged 0.8° warmer than the 1900s. The biggest change is in January (+3.0°).
A smaller shift than in 90% 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 Cortlandt Township compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Cortlandt Township’s place among South Dakota’s.
Cortlandt Township weather by month
Highs, lows and precipitation from NOAA’s grid at Cortlandt Township’s center; snow, wet days and snow on the ground from Ipswich, SD. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 22° | 3° | 0.5" | 6.0" | 4 | 24 | 0° – 28° |
| February | 27° | 7° | 0.6" | 6.8" | 4 | 19 | 1° – 29° |
| March | 40° | 20° | 0.9" | 5.4" | 5 | 13 | 19° – 44° |
| April | 56° | 31° | 1.9" | 4.0" | 6 | 4 | 34° – 50° |
| May | 68° | 44° | 3.2" | 0.0" | 8 | 0 | 52° – 63° |
| June | 78° | 55° | 3.5" | 0.0" | 9 | 0 | 62° – 71° |
| July | 83° | 60° | 3.1" | 0.0" | 7 | 0 | 63° – 76° |
| August | 82° | 57° | 2.4" | 0.0" | 6 | 0 | 64° – 74° |
| September | 73° | 47° | 2.1" | 0.0" | 5 | 0 | 54° – 65° |
| October | 58° | 34° | 1.9" | 1.1" | 5 | 1 | 38° – 50° |
| November | 41° | 21° | 0.7" | 4.7" | 3 | 6 | 18° – 40° |
| December | 27° | 9° | 0.6" | 5.7" | 4 | 16 | 4° – 26° |
| Year | 55° | 32° | 21.2" | 33.7" | 64 | 83 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 1° to 29°. June is the most reliable, staying within 10°.
Where Cortlandt 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 Cortlandt Township’s center.
- Snow: Ipswich, SD.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Ipswich, SD, 13 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 Cortlandt Township’s climate
What is the weather like in Cortlandt Township?
A typical July afternoon reaches 83°, a January night drops to 3°, and about 34 inches of snow falls in a normal winter. Colder January nights than all but 127 U.S. towns; cooler July afternoons than 66% of U.S. towns.
How cold does it get in Cortlandt Township in winter?
January nights average 3°. About 180 nights a year reach 32° or below and 37 reach 0° or below. In the coldest January of the last 30 years the month averaged 0°.
How much snow does Cortlandt Township get?
About 34 inches in a normal winter at Ipswich, SD, most of it in February, with snow on the ground about 83 days a year.
How hot does it get in Cortlandt Township?
July, with a typical high of 83° and a low of 60°. About 13 days a year reach 90° (Ipswich, SD).
When is the first and last frost in Cortlandt Township?
In half of years the last spring frost (32°) comes by May 8 and the first fall frost by September 29, about 143 frost-free days, at Ipswich, SD.
What growing zone is Cortlandt Township in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −24°.
What is the best time of year to visit Cortlandt 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 Cortlandt Township getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 90% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Cortlandt 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.