Blackhawk’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 83°, a January night drops to 14°, and about 36 inches of snow falls in a normal winter.
A year in Blackhawk at a glance
Each month’s typical high and low, and what it brings.
What stands out about Blackhawk’s climate
Compared with towns across the U.S., with Blackhawk’s place in South Dakota beside it.
What a year in Blackhawk 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 10 and the first by October 5. Frost and day counts come from NOAA’s station at Rapid City 4nw, SD, 3 miles from the town’s center, 380 ft lower.
The 2023 USDA map puts Blackhawk’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 36 inches of snow a winter
Snow, measured at Rapid City 4nw, SD, falls mostly in April. Precipitation (rain plus melted snow) adds up to 20 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 67 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Blackhawk
94% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Rapid City 4nw, SD.
Living with Blackhawk’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 10 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 5.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 3.9 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Blackhawk from natural hazards, river flooding is the largest share (43%); heat waves, cold waves, winter storms and ice storms together are 21%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Blackhawk and its neighbors
Every town next door is within a degree of Blackhawk in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Blackhawk’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Blackhawk, SD | 14° | 83° | 20" | 36" |
| Gleneagle, CO | 14° | 84° | 21" | 55" |
| Polson, MT | 20° | 83° | 19" | 34" |
| Raton, NM | 15° | 85° | 16" | 25" |
| Doney Park, AZ | 17° | 86° | 16" | 52" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Blackhawk averaged 1.4° warmer than the 1900s. The biggest change is in January (+3.9°).
A bigger shift than in 53% 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 Blackhawk compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Blackhawk’s place among South Dakota’s.
Blackhawk weather by month
Highs, lows and precipitation from NOAA’s grid at Blackhawk’s center; snow, wet days and snow on the ground from Rapid City 4nw, SD. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 38° | 14° | 0.3" | 3.9" | 3 | 5 | 17° – 36° |
| February | 38° | 15° | 0.5" | 6.1" | 4 | 7 | 11° – 36° |
| March | 47° | 24° | 1.1" | 6.2" | 4 | 4 | 23° – 47° |
| April | 55° | 31° | 2.2" | 7.9" | 7 | 2 | 36° – 49° |
| May | 64° | 41° | 4.1" | 0.9" | 9 | 0 | 46° – 58° |
| June | 75° | 50° | 3.3" | 0.0" | 10 | 0 | 57° – 69° |
| July | 83° | 57° | 2.8" | 0.0" | 9 | 0 | 62° – 76° |
| August | 82° | 55° | 2.0" | 0.0" | 6 | 0 | 64° – 73° |
| September | 73° | 46° | 1.5" | 0.0" | 5 | 0 | 53° – 66° |
| October | 59° | 34° | 1.6" | 2.1" | 5 | 1 | 38° – 52° |
| November | 47° | 24° | 0.5" | 4.0" | 3 | 3 | 26° – 44° |
| December | 38° | 16° | 0.4" | 5.0" | 2 | 6 | 18° – 33° |
| Year | 58° | 34° | 20.3" | 36.1" | 67 | 28 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 11° to 36°. August is the most reliable, staying within 10°.
Where Blackhawk’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 Blackhawk’s center.
- Snow: Rapid City 4nw, SD.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Rapid City 4nw, SD, 3 miles from the town’s center, 380 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 Blackhawk’s climate
What is the weather like in Blackhawk?
A typical July afternoon reaches 83°, a January night drops to 14°, and about 36 inches of snow falls in a normal winter. Colder January nights than 86% of U.S. towns; cooler July afternoons than 69% of U.S. towns.
How cold does it get in Blackhawk in winter?
January nights average 14°. About 170 nights a year reach 32° or below and 17 reach 0° or below. In the coldest January of the last 30 years the month averaged 17°.
How much snow does Blackhawk get?
About 36 inches in a normal winter at Rapid City 4nw, SD, most of it in April, with snow on the ground about 28 days a year.
How hot does it get in Blackhawk?
July, with a typical high of 83° and a low of 57°. About 20 days a year reach 90° and 1 reach 100° (Rapid City 4nw, SD).
When is the first and last frost in Blackhawk?
In half of years the last spring frost (32°) comes by May 10 and the first fall frost by October 5, about 147 frost-free days, at Rapid City 4nw, SD.
What growing zone is Blackhawk 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 Blackhawk?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Blackhawk getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 53% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Blackhawk.
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.