Signal, SD climate
Signal has cold, snowy winters and warm summers. A typical July afternoon reaches 89°, a January night drops to 10°, and about 37 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Signal feels like
Winter
Spring
Summer
Fall
Signal 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 | 32° | 10° | 0.5" | 5.5" | 3 | 15 | 13° – 36° |
| February | 37° | 14° | 0.7" | 5.9" | 4 | 11 | 12° – 36° |
| March | 49° | 25° | 1.2" | 5.5" | 5 | 9 | 27° – 51° |
| April | 61° | 35° | 2.9" | 7.7" | 7 | 3 | 39° – 54° |
| May | 72° | 47° | 3.7" | 0 | 9 | 0 | 55° – 66° |
| June | 82° | 57° | 3.7" | 0 | 8 | 0 | 65° – 75° |
| July | 89° | 63° | 2.9" | 0 | 7 | 0 | 67° – 83° |
| August | 86° | 61° | 3.0" | 0 | 5 | 0 | 67° – 77° |
| September | 78° | 51° | 2.5" | 0 | 4 | 0 | 58° – 70° |
| October | 63° | 37° | 2.0" | 2.0" | 5 | 1 | 42° – 55° |
| November | 48° | 24° | 0.8" | 6.9" | 4 | 8 | 26° – 45° |
| December | 35° | 14° | 0.6" | 3.7" | 3 | 13 | 13° – 31° |
| Year | 61° | 36° | 24.4" | 37.2" | 62 | 61 |
“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 Signal
Signal gets 24 inches of rain and melted snow a year. June is the wettest month and January the driest. Rain or snow falls on about 62 days a year. Snow covers the ground about 61 days of the year.
About 159 frost-free days a year
In half of years the last 32° night comes by May 3 and the first one by October 10. That leaves about 159 frost-free days for gardens, shorter than 72% of U.S. towns.
Heating and cooling a home in Signal
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Signal, 90% of that work is heating and 10% 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.
Signal and its neighbors
Signal borders 4 towns with climate data. January nights across them vary by 0.8°. Platte has the coldest January nights (10°) and Hamilton the hottest July afternoons (88°). Signal’s January low is 10° and its July high 89°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Signal 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 Signal averaged 0.9° warmer than the 1900s. The biggest change is in January (+3.1°). The shift is smaller than in 75% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Signal’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. March swings the most: between 1991 and 2020 its average temperature ranged from 27° to 51°. June is the most reliable, staying within 9°.
Common questions about Signal’s climate
What is the coldest month in Signal?
January, with a typical high of 32° and a low of 10°.
What is the hottest month in Signal?
July, with a typical high of 89° and a low of 63°. About 26 days a year reach 90°.
How much snow does Signal get?
About 37 inches in a normal winter, most of it in April.
When is the first frost in Signal?
In half of years the first 32° night comes by October 10, and the last spring frost by May 3.
What is the rainiest month in Signal?
June, with 3.7 inches of rain and melted snow. The year totals 24 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Signal itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Bonesteel, SD (10 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.