St. Onge, SD climate
St. Onge has cold, snowy winters and warm summers, with very little rain. A typical July afternoon reaches 87°, a January night drops to 14°, and about 42 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decade9° cooler than normal today. The forecast high is 59°, and a typical Oct 1 in St. Onge peaks around 68°.Live forecast: National Weather Service · Normal: NOAA 1991–2020
What a year in St. Onge feels like
Winter
Spring
Summer
Fall
St. Onge 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 | 36° | 14° | 0.6" | 5.5" | 5 | 16° – 36° |
| February | 38° | 16° | 0.8" | 6.7" | 5 | 8° – 36° |
| March | 49° | 24° | 1.2" | 7.2" | 5 | 24° – 47° |
| April | 58° | 32° | 2.4" | 5.2" | 7 | 38° – 51° |
| May | 67° | 43° | 4.0" | 1.3" | 10 | 47° – 60° |
| June | 78° | 52° | 3.4" | 0 | 10 | 60° – 71° |
| July | 87° | 59° | 2.3" | 0 | 8 | 65° – 78° |
| August | 85° | 56° | 1.8" | 0 | 7 | 65° – 76° |
| September | 76° | 47° | 1.5" | 0 | 6 | 55° – 67° |
| October | 60° | 34° | 2.0" | 2.6" | 8 | 38° – 53° |
| November | 47° | 24° | 0.9" | 3.9" | 5 | 25° – 45° |
| December | 37° | 16° | 0.7" | 9.8" | 5 | 17° – 34° |
| Year | 60° | 35° | 21.6" | 42.2" | 80 |
“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 St. Onge
St. Onge gets 22 inches of rain and melted snow a year. May is the wettest month and January the driest. Rain or snow falls on about 80 days a year.
About 143 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 143 frost-free days for gardens, shorter than 87% of U.S. towns.
Heating and cooling a home in St. Onge
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In St. Onge, 91% of that work is heating and 9% 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 St. Onge 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 St. Onge averaged 1.1° warmer than the 1900s. The biggest change is in March (+3.1°). The shift is smaller than in 63% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at St. Onge’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 8° to 36°. August is the most reliable, staying within 11°.
Common questions about St. Onge’s climate
What is the coldest month in St. Onge?
January, with a typical high of 36° and a low of 14°.
What is the hottest month in St. Onge?
July, with a typical high of 87° and a low of 59°. About 38 days a year reach 90°.
How much snow does St. Onge get?
About 42 inches in a normal winter, most of it in December.
When is the first frost in St. Onge?
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 St. Onge?
May, with 4.0 inches of rain and melted snow. The year totals 22 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for St. Onge itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Belle Fourche, SD (9 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.