Green Grass, SD climate
Green Grass has cold, snowy winters and warm summers, with very little rain. A typical July afternoon reaches 87°, a January night drops to 7°, and about 37 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Green Grass feels like
Winter
Spring
Summer
Fall
Green Grass 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 | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 28° | 7° | 0.4" | 5.2" | 3 | 17 | 7° – 32° |
| February | 31° | 11° | 0.6" | 7.4" | 3 | 13 | 2° – 33° |
| March | 44° | 21° | 0.9" | 6.0" | 3 | 11 | 21° – 47° |
| April | 57° | 31° | 1.8" | 5.9" | 6 | 3 | 37° – 50° |
| May | 68° | 43° | 3.0" | 0.3" | 8 | 0 | 50° – 62° |
| June | 79° | 53° | 3.4" | 0 | 9 | 0 | 61° – 71° |
| July | 87° | 59° | 2.6" | 0 | 7 | 0 | 64° – 80° |
| August | 85° | 57° | 1.9" | 0 | 4 | 0 | 65° – 76° |
| September | 76° | 47° | 1.4" | 0 | 3 | 0 | 55° – 67° |
| October | 59° | 34° | 1.6" | 1.6" | 4 | 1 | 38° – 52° |
| November | 43° | 21° | 0.5" | 5.1" | 2 | 8 | 20° – 42° |
| December | 31° | 11° | 0.5" | 5.3" | 2 | 12 | 9° – 29° |
| Year | 57° | 33° | 18.6" | 36.8" | 54 | 64 |
“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 Green Grass
Green Grass gets 19 inches of rain and melted snow a year. June is the wettest month and January the driest. Rain or snow falls on about 54 days a year. Snow covers the ground about 64 days of the year.
About 141 frost-free days a year
In half of years the last 32° night comes by May 10 and the first one by September 30. That leaves about 141 frost-free days for gardens, shorter than 88% of U.S. towns.
Heating and cooling a home in Green Grass
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Green Grass, 92% of that work is heating and 8% 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 Green Grass 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 Green Grass averaged 1.1° warmer than the 1900s. The biggest change is in January (+3.5°). The shift is smaller than in 64% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Green Grass’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 33°. June is the most reliable, staying within 10°.
Common questions about Green Grass’s climate
What is the coldest month in Green Grass?
January, with a typical high of 28° and a low of 7°.
What is the hottest month in Green Grass?
July, with a typical high of 87° and a low of 59°. About 24 days a year reach 90°.
How much snow does Green Grass get?
About 37 inches in a normal winter, most of it in February.
When is the first frost in Green Grass?
In half of years the first 32° night comes by September 30, and the last spring frost by May 10.
What is the rainiest month in Green Grass?
June, with 3.4 inches of rain and melted snow. The year totals 19 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Green Grass itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Eagle Butte, SD (10 mi, snow) and Timber Lake, SD (21 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.