Photo: TheCatalyst31 · CC BY 4.0Egan has some of the coldest winter nights among U.S. towns
In July the day’s top temperature is typically 83°. It is a dry place: less rain and snow fall here than on 86% of U.S. towns. Compared with 1901–2000, the average now sits 0.6° higher. The outdoor season runs from May to September, with highs of 69–83°.
A year in Egan at a glance
Each month’s typical high and low, and what it brings.
What stands out about Egan’s climate
Compared with towns across the U.S., with Egan’s place in South Dakota beside it.
What a year in Egan feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 148 frost-free days a year
In half of years the last 32° night comes by May 5 and the first by October 1. Frost and day counts come from NOAA’s station at Flandreau, SD, 4 miles from the town’s center, at about the same height.
The 2023 USDA map puts Egan’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 Flandreau, SD, falls mostly in February and December. Precipitation (rain plus melted snow) adds up to 28 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 82 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Egan
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 Flandreau, SD.
Living with Egan’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
148 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 1.
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 Egan from natural hazards, river flooding is the largest share (35%); heat waves, cold waves, winter storms and ice storms together are 34%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Egan and its neighbors
Every town next door is within a degree of Egan in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Egan’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 |
|---|---|---|---|---|
| Egan, SD | 5° | 83° | 28" | 40" |
| Anoka, MN | 5° | 82° | 31" | 44" |
| Hudson, WI | 6° | 82° | 33" | 50" |
| Wahpeton, ND | 1° | 82° | 25" | 50" |
| Fort Dodge, IA | 9° | 83° | 34" | 39" |
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 Egan averaged 0.6° warmer than the 1900s. The biggest change is in January (+2.4°).
A smaller shift than in 96% 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 Egan compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Egan’s place among South Dakota’s.
Egan weather by month
Highs, lows and precipitation from NOAA’s grid at Egan’s center; snow, wet days and snow on the ground from Flandreau, SD. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 24° | 5° | 0.6" | 5.8" | 5 | 4° – 28° |
| February | 29° | 9° | 0.8" | 8.2" | 6 | 6° – 31° |
| March | 41° | 21° | 1.4" | 6.2" | 6 | 21° – 46° |
| April | 56° | 33° | 2.7" | 4.8" | 8 | 34° – 52° |
| May | 69° | 45° | 3.7" | 0.1" | 10 | 52° – 64° |
| June | 78° | 56° | 4.4" | 0.0" | 10 | 63° – 72° |
| July | 83° | 60° | 3.6" | 0.0" | 8 | 63° – 78° |
| August | 80° | 58° | 3.4" | 0.0" | 7 | 63° – 73° |
| September | 73° | 49° | 3.0" | 0.0" | 6 | 54° – 66° |
| October | 59° | 36° | 2.1" | 1.2" | 6 | 40° – 52° |
| November | 42° | 22° | 1.1" | 5.6" | 5 | 22° – 43° |
| December | 28° | 11° | 0.8" | 8.5" | 6 | 6° – 26° |
| Year | 55° | 34° | 27.7" | 40.4" | 82 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 21° to 46°. June is the most reliable, staying within 9°.
Where Egan’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 Egan’s center.
- Snow: Flandreau, SD.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Flandreau, SD, 4 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 Egan’s climate
What is the weather like in Egan?
A typical July afternoon reaches 83°, a January night drops to 5°, and about 40 inches of snow falls in a normal winter. Colder January nights than 98% of U.S. towns; cooler July afternoons than 74% of U.S. towns.
How cold does it get in Egan in winter?
January nights average 5°. About 177 nights a year reach 32° or below and 36 reach 0° or below. In the coldest January of the last 30 years the month averaged 4°.
How much snow does Egan get?
About 40 inches in a normal winter at Flandreau, SD, most of it in February and December.
How hot does it get in Egan?
July, with a typical high of 83° and a low of 60°. About 9 days a year reach 90° (Flandreau, SD).
When is the first and last frost in Egan?
In half of years the last spring frost (32°) comes by May 5 and the first fall frost by October 1, about 148 frost-free days, at Flandreau, SD.
What growing zone is Egan 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 Egan?
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 Egan getting warmer?
Yes: 1991–2020 averaged 0.6° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 96% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Egan.
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.