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Shaded-relief map of Alcester, South Dakota: rivers, roads, the city limits and where the water drains.
SOUTH DAKOTA · UNION COUNTY

Alcester

772 people, 1,420 ft above sea level in Union County.

1,420 ftElevation, city center
772People, 2024 estimate
1 sq miLand area
Clear 39°
Clear now Dew point 25° · ESE 7 mph · high 38°
City of Alcester River Interstate 2 miles
Explore the plate Order a print

The Alcester plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.

MILE1
TODAY

Today in Alcester

NWS forecast and National Blend of Models · updated 5:00 PM CST
RIGHT NOW Le Mars Municipal Airport (KLRJ) · 5:35 PM
Clear
39° Clear Feels like 34° · high of 38° near 5 PM
WindESE 7 mphno gusts
Humidity56%rising to 96% by morning
Pressure30.20 in →steady
Visibility10 mihaze-free
CloudsClear
UV index—no forecast
Dew point 25° · Dry41° by Tuesday: more humid
DryComfortableStickyMuggyOppressive
NEXT RAIN
Rain
Friday90% chance · showers
LIKELY AMOUNT—amounts come within 3 days
LAST RAINNov. 50.1 in · 9 dry days
ALERTS & OUTLOOKS
No watches or warnings for Union County
NWS Sioux Falls and the Storm Prediction Center · checked 5:47 PM
SUN & MOON
↑ 7:17 AM5:04 PM ↓
9 h 46 m of daylight, 2 minutes less than yesterday
Waxing crescent, 26% lit. Next full moon: Nov. 24.
AIR & POLLEN
28
GOODAir quality index · ozone
No pollen source yet.

The next three days, hour by hour

Sky: clear, cloudy, night Rain likely National Blend of Models
SATURDAY, NOV. 14
SUNDAY, NOV. 15
MONDAY, NOV. 16
TUESDAY, NOV. 17
5p
8p
11p
2a
5a
8a
11a
2p
5p
8p
11p
2a
5a
8a
11a
2p
5p
8p
11p
2a
5a
8a
11a
2p
mostly clear night
partly cloudy night
partly cloudy night
mostly clear night
mostly clear night
mostly sunny
mostly sunny
mostly sunny
clear night
clear night
clear night
mostly clear night
partly cloudy night
partly cloudy day
mostly sunny
clear day
mostly clear night
mostly clear night
partly cloudy night
partly cloudy night
mostly cloudy night
mostly cloudy day
partly cloudy day
partly cloudy day
TEMPERATURE °F
38°
27°
48°
34°
53°
40°
CHANCE OF RAIN
50%
WIND, MPH
7
6
6
6
7
9
13
13
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17
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HOW IT FEELS · DEW POINT
Dry: dew points 26 to 31° ↑ Humid air returns More humid: 41° by Tuesday

The next seven days, and how sure we are

Forecast, with the range 8 in 10 ensemble members agree on Normal, about 80° / 62°
SAT Nov. 14 Partly cloudy Partly cloudy
38° 27°
0% rain — SE 6 A
SUN Nov. 15 Mostly sunny; warmer Mostly sunny; warmer
49° 33°
0% rain — S 11 B
MON Nov. 16 Mostly sunny Mostly sunny
54° 40°
0% rain — S 15, gusts 26 B
TUE Nov. 17 Partly cloudy Partly cloudy
55° 45°
0% rain — S 16, gusts 25 B
WED Nov. 18 Partly cloudy Partly cloudy
59° 42°
20% rain — SSW 13 C
THU Nov. 19 Mostly sunny Mostly sunny
53° 41°
20% rain — N 5 C
FRI Nov. 20 Showers likely Showers likely
59° 47°
90% rain 0.3–1.3″ SSE 14 C
How sure are we? AModels agree: highs within 4° BSome spread: within 8° CWide spread: check back
Range from the National Blend of Models percentiles · graded on Forecast Scores
AIR MAIL

Where today’s air came from

The air arriving over Alcester about 5,000 feet above the ground was over the southern Rockies three days ago, and over the southern Plains a day ago, about 950 miles back along its path. Most of the nine paths traced from around the city agree. It rose from near the ground on the way. Near the ground the air came from the Canadian Prairies; at 10,000 feet, from the central Plains. Traced back 72 hours through NOAA’s hourly RAP analyses, nine paths at each of three heights.

THIS WEEK, ONE YEAR AGO Nov. 15, 2025

The hottest this week has been

79° on Nov. 15, 2025, the hottest reading for this week of the year since 1897. Next is 78° in 1953.

78°
79°
19532025
Source: NOAA RCC-ACIS, the Centerville 6 SE record since 1897.
MILE2
THE GROUND

What Alcester stands on

Alcester’s center stands about 1,420 ft above sea level. Within three miles the land runs from 1,300 ft to 1,470 ft, a difference of 170 ft: gently rolling country.

Under the town center the state geologic map shows Carlile Shale, from the Late Cretaceous, 66 to 100 million years old.

The section below crosses 5 rock units mapped at the surface.

Alcester, cut in half from south to north

A section south to north, 24 miles through the town center
1,200 ft1,300 ft1,400 ft1,500 ft ALCESTER1,420 ftBig Sioux Riverabout 1,140 ftHigh point of the line1,550 ft ← S · AkronN →

Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 47×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.

Rock at the surface along the line

Carlile Shale

Shale. Age: Late Cretaceous, 66 to 100 million years old. About 18 mi of the line.

Niobrara Formation

Chalk, marlstone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 4 mi of the line.

Graneros Shale

Shale. Age: Late Cretaceous, 66 to 100 million years old. About 1 mi of the line.

Dakata and Windrow Formations

Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 0.7 mi of the line.

Greenhorn Formation

Shale, mudstone, marlstone. Age: Late Cretaceous, 66 to 100 million years old. About 0.3 mi of the line.

From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.

Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.

MILE3
THE WATER

Where Alcester’s rain goes

A raindrop that lands in Alcester reaches the Gulf of America by way of East Brule Creek, Brule Creek, the Big Sioux, the Missouri and the Mississippi: about 1,970 river miles.

THE WAY DOWN, TO SCALE
Alcester≈ 1,970 mi · the Gulf of America
FROM THE CENTER OF ALCESTER ≈ 1,970 mi to the Gulf of America East Brule Creek → Brule Creek → Big Sioux → Missouri → Mississippi

1,170 miles of the trip are on the Mississippi.

Traced down the USGS NHDPlus V2.1 river network from the Census center point of Alcester; river miles along the main stem, rounded.

MILE5
THE ALMANAC

Alcester’s year

1991–2020 normals · records since 1897 · Centerville 6 SE, 14 mi west

Alcester has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 7° in January. A normal year brings about 30 inches of snow; with the rain, that comes to about 27 inches of water.

27°7°32°11°45°23°58°34°70°47°80°58°84°62°82°59°75°50°61°36°45°23°31°12° JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 1234 TODAY ALCESTER 26.9 in rain and snowmelt
Normal high to low, by month Record high to low, by day Rain by month Freezing
July, average84° / 62°high / low, the warmest month
January, average27° / 7°high / low, the coldest month
Rain and melted snow26.9 inwettest months: June and May
Snow a year30.5 insnowiest: December
Hottest on record113°FJuly 17, 1936
Coldest on record−44°FJanuary 12, 1912
Wettest day on record6.02 inJuly 14, 1900
Snowiest day on record22.0 inFebruary 18, 1962
90° days a year18very few reach 100°
Nights at or below 32°164and 63 days that stay below freezing
Climate typeHot-summer humid continentalKöppen Dfa

AROUND THE RING

1Freeze seasonfrom the first fall freeze, about Oct. 2, to the last in spring, about April 30 (median dates)
2Highs below freezingDec. 12 to Feb. 17; normal highs stay below 32°
3Lows below freezingOct. 24 to April 11; normal lows fall below 32°
4Wettest stretchMay through July: 11.2 of the year’s 26.9 inches
NOVEMBER 14 IN THE RECORD

On November 14 Alcester normally reaches 46° and falls to 23°. The record high is 76°, in 1999; the record low −19°, in 1959. The most rain on this date, 1.54 in, fell in 1926.

MONTH BY MONTH
JanFebMarAprMayJunJulAugSepOctNovDec
Normal high27°32°45°58°70°80°84°82°75°61°45°31°
Normal low7°11°23°34°47°58°62°59°50°36°23°12°
Rain and melt, in0.440.631.382.693.874.293.053.203.122.321.230.66
Snow, inches5.26.04.52.90.10.00.00.00.00.75.06.1
Record high70° (2002)73° (2017)93° (2026)97° (1926)109° (1934)108° (1931)113° (1936)111° (1936)106° (1971)95° (2015)82° (1999)67° (1998)
Record low−44° (1912)−35° (1936)−21° (2014)−6° (2018)19° (1967)33° (1935)38° (1971)32° (1986)19° (1984)−6° (1925)−20° (1977)−39° (1917)

Normals 1991–2020 and records since 1897 at Centerville 6 SE, 14 miles west, 140 ft lower. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around Alcester on the Forecast Network

Neighboring plates

Sioux Falls SD · 36 MI 36 miles north Sioux City IA · 39 MI 39 miles south Omaha NE · 125 MI 125 miles south West Des Moines IA · 178 MI 178 miles southeast Ankeny IA · 179 MI 179 miles southeast Des Moines IA · 184 MI 184 miles southeast
FORECASTCITY
Map of Alcester, South Dakota. Explore the plate
SOUTH DAKOTA · UNION

Alcester

772 people, 1,420 ft above sea level in Union County.

1,420 ftElevation
772People
1 sq miLand
Clear 39°
ClearDew point 25°
1

Today in Alcester

NEXT 15 HOURS
Now mostly clear night 38° 0%
8p mostly clear night 35° 0%
11p partly cloudy night 31° 0%
2a mostly clear night 29° 0%
5a mostly clear night 28° 0%
8a mostly sunny 28° 0%
Rain
NEXT RAINFriday · 90%
→
Sat0%
Partly cloudy Partly cloudy
27
38
A
Sun0%
Mostly sunny; warmer Mostly sunny; warmer
33
49
B
Mon0%
Mostly sunny Mostly sunny
40
54
B
Tue0%
Partly cloudy Partly cloudy
45
55
B
Wed20%
Partly cloudy Partly cloudy
42
59
C
Thu20%
Mostly sunny Mostly sunny
41
53
C
Fri90%
Showers likely Showers likely
47
59
C
Letters show how sure the forecast is: A, models agree; B, some spread; C, check back. Sample data.
THIS WEEK, ONE YEAR AGO · NOV. 15, 2025

79°, the hottest this week of the year has been since 1897.

2

What Alcester stands on

Alcester’s center stands about 1,420 ft above sea level. Within three miles the land runs from 1,300 ft to 1,470 ft, a difference of 170 ft: gently rolling country.

Alcester, south to north Alcester1,420 ftBig Sioux Riverabout 1,140 ft ← SN → 24 miles through the town center; vertical exaggeration about 89×. Colors: rock at the surface.
Elevation, center1,420 ft
Within 3 miles1,300 to 1,470 ft
Lie of the landGently rolling (170 ft of relief)
Rock at the surfaceCarlile Shale
Its ageLate Cretaceous, 66 to 100 million years old
5

Alcester’s year

Alcester has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 7° in January. A normal year brings about 30 inches of snow; with the rain, that comes to about 27 inches of water.

JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 1234 26.9 in
July, average84° / 62° · high / low, the warmest month
January, average27° / 7° · high / low, the coldest month
Rain and melted snow26.9 in · wettest months: June and May
Snow a year30.5 in · snowiest: December
Hottest on record113°F · July 17, 1936
Coldest on record−44°F · January 12, 1912
Wettest day on record6.02 in · July 14, 1900
Snowiest day on record22.0 in · February 18, 1962
90° days a year18 · very few reach 100°
Nights at or below 32°164 · and 63 days that stay below freezing
Climate typeHot-summer humid continental · Köppen Dfa
1Freeze season · from the first fall freeze, about Oct. 2, to the last in spring, about April 30 (median dates)
2Highs below freezing · Dec. 12 to Feb. 17; normal highs stay below 32°
3Lows below freezing · Oct. 24 to April 11; normal lows fall below 32°
4Wettest stretch · May through July: 11.2 of the year’s 26.9 inches
NOVEMBER 14 IN THE RECORD

On November 14 Alcester normally reaches 46° and falls to 23°. The record high is 76°, in 1999; the record low −19°, in 1959. The most rain on this date, 1.54 in, fell in 1926.

Normals 1991–2020 and records since 1897 at Centerville 6 SE, 14 miles west, 140 ft lower. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 1,970 mito the Gulf of AmericaEast Brule Creek → Brule Creek → Big Sioux → Missouri → Mississippi

A raindrop that lands in Alcester reaches the Gulf of America by way of East Brule Creek, Brule Creek, the Big Sioux, the Missouri and the Mississippi: about 1,970 river miles.

1,170 miles of the trip are on the Mississippi.