Dry weather: only 20 inches of rain and melted snow a year in Porcupine, less than in 89% of U.S. towns
Midsummer highs settle at about 87°. In January, nights here are colder than in 88% of U.S. towns. Decade by decade the climate has edged up, 1.6° above 1901–2000. If you like long walks, May, June and September offer highs of 68–79°.
A year in Porcupine at a glance
Each month’s typical high and low, and what it brings.
What stands out about Porcupine’s climate
Compared with towns across the U.S., with Porcupine’s place in South Dakota beside it.
What a year in Porcupine feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 147 frost-free days a year
In half of years the last 32° night comes by May 9 and the first by October 4. Frost and day counts come from NOAA’s station at Manderson 3 Ne, SD, 5 miles from the town’s center, 100 ft lower.
The 2023 USDA map puts Porcupine’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −17°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 20 inches of rain a year
June is the wettest month and January the driest.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Porcupine
90% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Manderson 3 Ne, SD.
Living with Porcupine’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
147 frost-free days in zone 5a. The last frost comes by May 9 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 4.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 5.5 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Porcupine from natural hazards, wildfire is the largest share (39%); heat waves, cold waves, winter storms and ice storms together are 16%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Porcupine and similar climates
TownRatings has no climate map of the towns around Porcupine yet.
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
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°).
A bigger shift than in 64% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Porcupine compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Porcupine’s place among South Dakota’s.
Porcupine weather by month
Highs, lows and precipitation from NOAA’s grid at Porcupine’s center. 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" |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 25° to 50°. August is the most reliable, staying within 10°.
Where Porcupine’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Porcupine’s center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Manderson 3 Ne, SD, 5 miles from the town’s center, 100 ft lower; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Porcupine’s climate
What is the weather like in Porcupine?
A typical July afternoon reaches 87°, a January night drops to 14°. Colder January nights than 88% of U.S. towns; hotter July afternoons than 64% of U.S. towns.
How cold does it get in Porcupine in winter?
January nights average 14°. About 164 nights a year reach 32° or below and 15 reach 0° or below. In the coldest January of the last 30 years the month averaged 16°.
How hot does it get in Porcupine?
July, with a typical high of 87° and a low of 60°. About 38 days a year reach 90° and 4 reach 100° (Manderson 3 Ne, SD).
When is the first and last frost in Porcupine?
In half of years the last spring frost (32°) comes by May 9 and the first fall frost by October 4, about 147 frost-free days, at Manderson 3 Ne, SD.
What growing zone is Porcupine in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −17°.
What is the best time of year to visit Porcupine?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Porcupine getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 64% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Porcupine.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.