Eureka, SD Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Eureka's primary NOAA station, EUREKA.
The climate verdict for Eureka
Winter sets the terms in Eureka, South Dakota. A pronounced 58.8°F seasonal swing and heating demand above twice the cooling total frame an annual average of 42°F. At 49/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 18% of scores.
- 42°F
- average temperature, NOAA 1991-2020 normal
- 49/100
- comfort score, above 18% of station-mapped location scores
- 20.3"
- annual precipitation · 44" snow
- 138 days
- frost-free days per growing season
Eureka: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00392797 · Eureka, SD 42°F mean · 20.3" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 42°F
- RANK-COOL #617
- PHOTO-FINISH ≈ Williston Sloul…
- PRCP-DRY 20.3"
- SWING-WIDE 59°F
- COMF-LOW 49/100
- LOAD-HEAT 8,874 HDD
- STN-1 USC00392797
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Williston Sloulin, ND ( -0.1 °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.
- Eureka (this station) 42°F
- Cold Steele, ND 42°F
- Near Williston Sloul…, ND 42°F
- Near Castlewood, SD 42°F
- Near Walker, MN 42°F
Climate Living Index · Eureka
Eureka: 22/100 · grade F
Eureka publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Eureka, not an official NOAA rating. Rankings still use Comfort Score 49/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 20.3 in · 14.8 from 35 in | 48/100 · D |
| Snowfall burden | 44.3 inches/year | 24/100 · F |
| Normal heat + freeze calendar | 189 calendar days | 20/100 · F |
| Frost-free season | 138 days/year | 17/100 · F |
| Annual temperature balance | 41.8°F · 25.7° from 67.5°F | 9/100 · F |
Eureka · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Eureka is a continental Köppen climate: Dwb
Coldest-month mean 11.2°F and warmest-month mean 70.0°F place this station in continental, dry-winter, warm summer climates (Dwb). Class Dwb is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: continental, specifically continental, dry-winter, warm summer.
- Köppen code
- Dwb
- Group
- Continental
- Warmest month
- 70.0°F
- Coldest month
- 11.2°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 Eureka sits across the climate record
Three NOAA fields for Eureka's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 91%
- Among 6,861 stations, Eureka sits in the cooler third of annual means.
- Annual precipitation
- Drier than 72%
- Eureka's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Wider than 97%
- Warmest-to-coldest month gap for Eureka is large versus 6,861 complete station-years.
How Eureka compares across U.S. station-mapped locations
Eureka's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
49 18th percentile score exceeds 18% 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%). This entry sits in this band.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 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
Eureka's measured station temperature trend
MethodologyAcross 86 complete annual observations from 1910 to 2025, EUREKA warmed at a fitted rate of 0.06°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Eureka primary station fitted change +0.06 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 21°F (-6°C) | 2°F (-17°C) | 11°F (-12°C) | 0.4" | 6.9" | 31.0 | 0.0 |
| February | 25°F (-4°C) | 6°F (-15°C) | 15°F (-9°C) | 0.5" | 7.6" | 27.6 | 0.0 |
| March | 38°F (3°C) | 18°F (-8°C) | 28°F (-2°C) | 0.8" | 8.5" | 27.8 | 0.0 |
| April | 54°F (12°C) | 30°F (-1°C) | 42°F (5°C) | 1.6" | 4.7" | 16.3 | 0.0 |
| May | 67°F (19°C) | 42°F (6°C) | 55°F (13°C) | 3.2" | 0.0" | 2.8 | 0.4 |
| June | 76°F (24°C) | 53°F (12°C) | 65°F (18°C) | 3.8" | 0.0" | 0.0 | 1.1 |
| July | 82°F (28°C) | 58°F (14°C) | 70°F (21°C) | 3.1" | 0.0" | 0.0 | 6.0 |
| August | 81°F (27°C) | 56°F (13°C) | 68°F (20°C) | 2.2" | 0.0" | 0.0 | 4.7 |
| September | 72°F (22°C) | 46°F (8°C) | 59°F (15°C) | 1.8" | 0.0" | 1.4 | 1.3 |
| October | 56°F (13°C) | 32°F (0°C) | 44°F (7°C) | 1.7" | 2.0" | 13.9 | 0.1 |
| November | 39°F (4°C) | 19°F (-7°C) | 29°F (-2°C) | 0.5" | 6.3" | 26.8 | 0.0 |
| December | 25°F (-4°C) | 8°F (-13°C) | 17°F (-9°C) | 0.5" | 8.3" | 30.9 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 83°F around July 24, short of 90°F on every date, while 189 dates carry a normal low at or below freezing, the coldest 1°F near January 20.
The freezing stretch
The normal low stays at or below 32°F into April 21, then returns to freezing around October 16, covering 189 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 14, when 35% of years recorded at least a hundredth of an inch. The driest is December 1 at 13%. Summed across the calendar, that is about 79 wet dates a year.
The widest day
September 14 carries the biggest normal gap between afternoon and dawn, 26°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Eureka.
Where Eureka Stands Nationally
Freezing is routine here by normals standards — the normal low reaches 32°F or colder on about 189 nights a year, more than most ranked stations.
Eureka earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 6.9"
4.8 days with precipitation
Snow: 7.6"
5.0 days with precipitation
Snow: 8.5"
5.6 days with precipitation
Snow: 4.7"
6.8 days with precipitation
9.1 days with precipitation
10.7 days with precipitation
8.6 days with precipitation
7.1 days with precipitation
6.3 days with precipitation
Snow: 2.0"
6.2 days with precipitation
Snow: 6.3"
4.2 days with precipitation
Snow: 8.3"
4.5 days with precipitation
Eureka runs a summer-peaked wet season
45% of Eureka'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 June at 3.8", on a wide 58.8°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: June, May, July, taking 50% of the annual total between them.
- Driest month: January at 0.4".
- Winter share: 7% 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 Eureka's precipitation splits across the calendar
About 79 days a year record measurable precipitation here, carrying 20.2" between them, or roughly 0.26 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 Eureka
Eureka averages 44.3 inches of snowfall a year, with March the snowiest month on the normals, spread across roughly 20 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: 44.3 inches of depth.
- Days recording measurable snow: about 20 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 22% 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
September 27
50% probability date
Last Spring Freeze
May 12
50% probability date
Growing Season
138 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
8,874
Higher = more heating needed
Cooling Degree Days
447
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside SD closest to Eureka 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 (42°F here).
- Big Bay, MI 42°F · 0.0°F off
- Lamoille, NV 42°F · 0.0°F off
- Medford, WI 42°F · 0.0°F off
- Milaca, MN 42°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (20.3" here), excluding temperature-peer places.
- Brewster, KS 20.3" · 0.0" off
- Richmond, UT 20.3" · 0.0" off
- Petersburg, ND 20.2" · 0.0" off
- Rolette, ND 20.2" · 0.0" off
Snow and freeze rhythm
When cold and snow define Eureka
heating led · moderate · high swing
Winter and seasonal range jointly define this record. Eureka logs 8,874 heating degree days, more than twice its 447 cooling total, while the typical coldest-to-warmest-month gap reaches 58.8°F. The annual mean therefore compresses two materially different seasons.
Only about 138 days are frost-free in a normal year. That short interval is consistent with the cold-season signal, but the measure does not predict the exact first or last freeze in any one year.
-
1. Eureka coldest normal
January
Averaging 11°F (-12°C), this month sits below freezing for the month as a whole, not merely overnight.
-
2. Eureka typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Eureka snow peak
March
Eureka averages 44.3 inches of snow a year, with March the snowiest month on the normals.
Questions about Eureka's climate
How much snow does Eureka get? ▼
How cold does Eureka get in winter? ▼
How much energy does heating and cooling require in Eureka? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Eureka's primary station: EUREKA (USC00392797). 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 4620180). Match rule for Eureka: 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 Eureka 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.