Photo: Magicpiano · CC BY-SA 4.0Dry weather: only 19 inches of rain and melted snow a year in Hermosa, less than in 90% of U.S. towns
Sunny July days climb to about 86°. A year here swings 72° from midwinter lows to midsummer highs. Its January nights bite harder than in 88% of U.S. towns. For walks and days out, May, June and September bring highs of 66–77°.
A year in Hermosa at a glance
Each month’s typical high and low, and what it brings.
What stands out about Hermosa’s climate
Compared with towns across the U.S., with Hermosa’s place in South Dakota beside it.
What a year in Hermosa feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 139 frost-free days a year
In half of years the last 32° night comes by May 12 and the first by October 1. Frost and day counts come from NOAA’s station at Rapid City Rgnl Airport, 16 miles from the town’s center, 200 ft lower.
The 2023 USDA map puts Hermosa’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −16°. 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 33 inches of snow a winter
Snow, measured at Hermosa 3 Ssw, SD, is heaviest from February through April, about 6 inches a month. Precipitation (rain plus melted snow) adds up to 19 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 77 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Hermosa
92% 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 Rgnl Airport.
Living with Hermosa’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
139 frost-free days in zone 5a. The last frost comes by May 12 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 1.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 0.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Hermosa from natural hazards, wildfire is the largest share (47%); heat waves, cold waves, winter storms and ice storms together are 6%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Hermosa and similar climates
TownRatings has no climate map of the towns around Hermosa yet.
Climates most like Hermosa’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 |
|---|---|---|---|---|
| Hermosa, SD | 14° | 86° | 19" | 33" |
| Cimarron Hills, CO | 18° | 85° | 17" | 33" |
| Raton, NM | 15° | 85° | 16" | 25" |
| Lockwood, MT | 15° | 88° | 15" | 35" |
| North Platte, NE | 14° | 89° | 21" | 28" |
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 Hermosa averaged 1.4° warmer than the 1900s. The biggest change is in January (+4.0°).
A bigger shift than in 56% 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 Hermosa compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Hermosa’s place among South Dakota’s.
Hermosa weather by month
Highs, lows and precipitation from NOAA’s grid at Hermosa’s center; snow, wet days and snow on the ground from Hermosa 3 Ssw, SD. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 38° | 14° | 0.3" | 5.4" | 3 | 18° – 36° |
| February | 39° | 15° | 0.5" | 6.1" | 4 | 12° – 36° |
| March | 49° | 24° | 0.9" | 5.7" | 5 | 24° – 48° |
| April | 57° | 32° | 2.1" | 5.7" | 8 | 37° – 50° |
| May | 66° | 42° | 3.8" | 0.5" | 11 | 48° – 60° |
| June | 77° | 52° | 3.2" | 0.0" | 11 | 58° – 71° |
| July | 86° | 58° | 2.7" | 0.0" | 9 | 64° – 78° |
| August | 85° | 56° | 2.0" | 0.0" | 7 | 65° – 75° |
| September | 76° | 47° | 1.4" | 0.0" | 6 | 55° – 67° |
| October | 61° | 34° | 1.3" | 1.4" | 6 | 39° – 53° |
| November | 48° | 24° | 0.5" | 4.0" | 3 | 27° – 45° |
| December | 39° | 15° | 0.4" | 4.2" | 3 | 17° – 33° |
| Year | 60° | 34° | 19.1" | 33.0" | 77 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 12° to 36°. August is the most reliable, staying within 10°.
Where Hermosa’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 Hermosa’s center.
- Snow: Hermosa 3 Ssw, SD.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Rapid City Rgnl Airport, 16 miles from the town’s center, 200 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 Hermosa’s climate
What is the weather like in Hermosa?
A typical July afternoon reaches 86°, a January night drops to 14°, and about 33 inches of snow falls in a normal winter. Colder January nights than 88% of U.S. towns; hotter July afternoons than 55% of U.S. towns.
How cold does it get in Hermosa in winter?
January nights average 14°. About 174 nights a year reach 32° or below and 18 reach 0° or below. In the coldest January of the last 30 years the month averaged 18°.
How much snow does Hermosa get?
About 33 inches in a normal winter at Hermosa 3 Ssw, SD, heaviest from February through April, about 6 inches a month.
How hot does it get in Hermosa?
July, with a typical high of 86° and a low of 58°. About 32 days a year reach 90° and 5 reach 100° (Rapid City Rgnl Airport).
When is the first and last frost in Hermosa?
In half of years the last spring frost (32°) comes by May 12 and the first fall frost by October 1, about 139 frost-free days, at Rapid City Rgnl Airport.
What growing zone is Hermosa in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −16°.
What is the best time of year to visit Hermosa?
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 Hermosa getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 56% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Hermosa.
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.