Porcupine, SD climate
Porcupine has cold winters and warm summers, with very little rain. A typical July afternoon reaches 87°, a January night drops to 14°.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Porcupine feels like
Winter
Spring
Summer
Fall
Porcupine weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 36° | 14° | 0.5" | 16° – 37° |
| February | 39° | 16° | 0.6" | 14° – 38° |
| March | 50° | 25° | 1.2" | 25° – 50° |
| April | 58° | 33° | 2.3" | 39° – 51° |
| May | 68° | 43° | 3.4" | 49° – 61° |
| June | 79° | 53° | 3.4" | 61° – 72° |
| July | 87° | 60° | 2.3" | 65° – 79° |
| August | 86° | 58° | 2.1" | 67° – 77° |
| September | 77° | 48° | 1.5" | 55° – 68° |
| October | 62° | 35° | 1.7" | 39° – 55° |
| November | 48° | 23° | 0.7" | 25° – 45° |
| December | 38° | 15° | 0.5" | 17° – 34° |
| Year | 61° | 35° | 20.0" |
“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 Porcupine
Porcupine gets 20 inches of rain and melted snow a year. June is the wettest month and January the driest.
About 147 frost-free days a year
In half of years the last 32° night comes by May 9 and the first one by October 4. That leaves about 147 frost-free days for gardens, shorter than 83% of U.S. towns.
Heating and cooling a home in Porcupine
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Porcupine, 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.
How Porcupine 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 Porcupine averaged 1.6° warmer than the 1900s. The biggest change is in January (+4.2°). The shift is larger than in 74% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Porcupine’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 25° to 50°. August is the most reliable, staying within 10°.
Common questions about Porcupine’s climate
What is the coldest month in Porcupine?
January, with a typical high of 36° and a low of 14°.
What is the hottest month in Porcupine?
July, with a typical high of 87° and a low of 60°. About 38 days a year reach 90°.
When is the first frost in Porcupine?
In half of years the first 32° night comes by October 4, and the last spring frost by May 9.
What is the rainiest month in Porcupine?
June, with 3.4 inches of rain and melted snow. The year totals 20 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Porcupine itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Manderson 3 Ne, SD (5 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.