Eureka, SD climate
Eureka has cold, snowy winters and pleasant summers, with very little rain. A typical July afternoon reaches 83°, a January night drops to 3°, and about 44 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Eureka feels like
Winter
Spring
Summer
Fall
Eureka weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 22° | 3° | 0.4" | 6.9" | 5 | -1° – 26° |
| February | 26° | 7° | 0.6" | 7.6" | 5 | -2° – 29° |
| March | 39° | 18° | 0.9" | 8.5" | 6 | 18° – 44° |
| April | 54° | 30° | 1.6" | 4.7" | 7 | 32° – 49° |
| May | 67° | 42° | 3.1" | 0 | 9 | 48° – 60° |
| June | 77° | 53° | 3.6" | 0 | 11 | 59° – 69° |
| July | 83° | 58° | 3.0" | 0 | 9 | 62° – 77° |
| August | 81° | 56° | 2.3" | 0 | 7 | 63° – 74° |
| September | 72° | 46° | 1.9" | 0 | 6 | 53° – 64° |
| October | 56° | 33° | 1.7" | 2.0" | 6 | 36° – 50° |
| November | 40° | 19° | 0.6" | 6.3" | 4 | 16° – 39° |
| December | 27° | 9° | 0.6" | 8.3" | 5 | 4° – 25° |
| Year | 54° | 31° | 20.1" | 44.3" | 79 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Eureka
Eureka gets 20 inches of rain and melted snow a year. June is the wettest month and January the driest. Rain or snow falls on about 79 days a year.
About 137 frost-free days a year
In half of years the last 32° night comes by May 12 and the first one by September 27. That leaves about 137 frost-free days for gardens, shorter than 91% of U.S. towns.
Heating and cooling a home in Eureka
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Eureka, 95% of that work is heating and 5% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Eureka compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Eureka averaged 0.7° warmer than the 1900s. The biggest change is in January (+2.8°). The shift is smaller than in 91% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Eureka’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from -2° to 29°. June is the most reliable, staying within 10°.
Common questions about Eureka’s climate
What is the coldest month in Eureka?
January, with a typical high of 22° and a low of 3°.
What is the hottest month in Eureka?
July, with a typical high of 83° and a low of 58°. About 14 days a year reach 90°.
How much snow does Eureka get?
About 44 inches in a normal winter, most of it in March.
When is the first frost in Eureka?
In half of years the first 32° night comes by September 27, and the last spring frost by May 12.
What is the rainiest month in Eureka?
June, with 3.6 inches of rain and melted snow. The year totals 20 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Eureka itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Eureka, SD (1 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.