Armour, SD Climate: Temperature & Rain by Month
Average temperature and precipitation from NOAA NCEI 1991–2020 normals →, with a derived climate comfort score
30-year climate normals (1991-2020) from Armour's primary NOAA station, ARMOUR.
The climate verdict for Armour
Armour, South Dakota has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 49°F. Its climate comfort score of 59/100 (moderate) lands mid-pack nationally, exceeding 37% of station-mapped location scores.
- 49°F
- yearly average temperature, NOAA normal
- 59/100
- comfort score, above 37% of station-mapped location scores
- 25.4"
- annual precipitation · 34" snow
- 156 days
- frost-free days per growing season
Armour: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00390296 · Armour, SD 49°F mean · 25.4" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-MID · SWING-WIDE · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 49°F
- RANK-COOL #2,401
- PHOTO-FINISH ≈ Cedar Butte
- PRCP-MID 25.4"
- SWING-WIDE 54°F
- COMF-MID 59/100
- LOAD-HEAT 6,747 HDD
- STN-1 USC00390296
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Cedar Butte, SD (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every SD station list.
- Armour (this station) 49°F
- Cold Vermillion, SD 49°F
- Hot Pickstown, SD 49°F
- Near Cedar Butte, SD 49°F
- Near Perry, IA 49°F
Climate Living Index · Armour
Armour: 41/100 · grade D
Armour publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Armour, not an official NOAA rating. Rankings still use Comfort Score 59/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 25.4 in · 9.6 from 35 in | 66/100 · C |
| Normal heat + freeze calendar | 161 calendar days | 39/100 · F |
| Annual temperature balance | 48.9°F · 18.6° from 67.5°F | 36/100 · F |
| Snowfall burden | 34.4 inches/year | 34/100 · F |
| Frost-free season | 156 days/year | 30/100 · F |
Armour · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Armour is a continental Köppen climate: Dfa
Coldest-month mean 20.9°F and warmest-month mean 75.0°F place this station in continental, no dry season, hot summer climates (Dfa). Class Dfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: continental, specifically continental, no dry season, hot summer.
- Köppen code
- Dfa
- Group
- Continental
- Warmest month
- 75.0°F
- Coldest month
- 20.9°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Armour sits across the climate record
Three NOAA fields for Armour's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 35th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 35th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Wider than 91%
- Warmest-to-coldest month gap for Armour is large versus 6,861 complete station-years.
How Armour compares across U.S. station-mapped locations
Armour's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
59 37th percentile score exceeds 37% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). This entry sits in this band.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 32°F (0°C) | 10°F (-12°C) | 21°F (-6°C) | 0.6" | 6.1" | 30.6 | 0.0 |
| February | 37°F (3°C) | 14°F (-10°C) | 26°F (-4°C) | 0.9" | 5.5" | 26.0 | 0.0 |
| March | 50°F (10°C) | 24°F (-4°C) | 37°F (3°C) | 1.2" | 6.3" | 23.7 | 0.0 |
| April | 62°F (17°C) | 35°F (2°C) | 49°F (9°C) | 3.3" | 4.1" | 10.5 | 0.3 |
| May | 73°F (23°C) | 46°F (8°C) | 60°F (15°C) | 4.0" | 0.0" | 1.1 | 0.8 |
| June | 82°F (28°C) | 58°F (14°C) | 70°F (21°C) | 3.7" | 0.0" | 0.0 | 4.4 |
| July | 88°F (31°C) | 62°F (17°C) | 75°F (24°C) | 2.7" | 0.0" | 0.0 | 12.4 |
| August | 86°F (30°C) | 60°F (16°C) | 73°F (23°C) | 2.8" | 0.0" | 0.0 | 10.0 |
| September | 79°F (26°C) | 52°F (11°C) | 65°F (19°C) | 2.4" | 0.0" | 0.6 | 5.1 |
| October | 64°F (18°C) | 38°F (3°C) | 51°F (11°C) | 2.1" | 1.2" | 8.3 | 0.4 |
| November | 48°F (9°C) | 25°F (-4°C) | 36°F (2°C) | 1.0" | 6.1" | 24.4 | 0.0 |
| December | 35°F (1°C) | 14°F (-10°C) | 25°F (-4°C) | 0.7" | 5.1" | 30.1 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 89°F around July 18, short of 90°F on every date, while 161 dates carry a normal low at or below freezing, the coldest 10°F near January 17.
The freezing stretch
The normal low stays at or below 32°F into April 6, then returns to freezing around October 29, covering 161 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is June 3, when 35% of years recorded at least a hundredth of an inch. The driest is December 18 at 10%. Summed across the calendar, that is about 77 wet dates a year.
The widest day
September 21 carries the biggest normal gap between afternoon and dawn, 28°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Armour.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 6.1"
3.8 days with precipitation
Snow: 5.5"
4.5 days with precipitation
Snow: 6.3"
5.2 days with precipitation
Snow: 4.1"
9.0 days with precipitation
9.5 days with precipitation
9.8 days with precipitation
8.6 days with precipitation
7.0 days with precipitation
6.1 days with precipitation
Snow: 1.2"
6.1 days with precipitation
Snow: 6.1"
4.1 days with precipitation
Snow: 5.1"
2.6 days with precipitation
Armour runs a summer-peaked wet season
36% of Armour's yearly precipitation falls in June, July and August alone, against the 25% an evenly spread year would give those three months. The wettest month is May at 4.0", on a wide 54.1°F gap between its warmest and coldest month. Warm-season convection and, across the Southwest, the North American monsoon produce this shape: rain arrives in short heavy bursts during the hottest part of the year rather than as long cool-season soaking.
- Wettest three months: May, June, April, taking 43% of the annual total between them.
- Driest month: January at 0.6".
- Winter share: 8% falls in December, January and February.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A summer-peaked label means the June-August share reaches 35%; it describes timing across an average year, not any single season, and says nothing about how heavy an individual storm can be.
How Armour's precipitation splits across the calendar
About 76 days a year record measurable precipitation here, carrying 25.4" between them, or roughly 0.33 inches on a typical wet day. That sits in the middle band: neither the many-light-days pattern of the Pacific Northwest and the Great Lakes, nor the few-heavy-events pattern of the Gulf and the desert Southwest.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year and say nothing about the heaviest single storm on record.
Winter brings real snow to Armour
Armour averages 34.4 inches of snowfall a year, with March the snowiest month on the normals, spread across roughly 17 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 34.4 inches of depth.
- Days recording measurable snow: about 17 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 14% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
October 6
50% probability date
Last Spring Freeze
May 3
50% probability date
Growing Season
156 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
6,747
Higher = more heating needed
Cooling Degree Days
929
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside SD closest to Armour on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (49°F here).
- Basin, WY 49°F · 0.0°F off
- Castle Dale, UT 49°F · 0.0°F off
- Colville, WA 49°F · 0.0°F off
- El Rito, NM 49°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (25.4" here), excluding temperature-peer places.
- Anson, TX 25.4" · 0.0" off
- Red Cloud, NE 25.5" · 0.0" off
- Raymondville, TX 25.5" · 0.0" off
- Rye, CO 25.4" · 0.1" off
Snow and freeze rhythm
When cold and snow define Armour
heating led · moderate · mid swing
Armour's energy balance leans toward cold weather: 6,747 annual heating degree days against 929 for cooling. Its 54.1°F seasonal range still makes the monthly rows more useful than the annual average alone.
Armour's frost-free season lasts about 156 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
-
1. Armour coldest normal
January
Averaging 21°F (-6°C), this month sits below freezing for the month as a whole, not merely overnight.
-
2. Armour typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Armour snow peak
March
Armour averages 34.4 inches of snow a year, with March the snowiest month on the normals.
Questions about Armour's climate
How much snow does Armour get? ▼
How many days above 90°F does Armour get? ▼
How much energy does heating and cooling require in Armour? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Armour's primary station: ARMOUR (USC00390296). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 4602260). Match rule for Armour: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Armour comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.