Severe Thunderstorm Watch 5:00 AM Severe Thunderstorm Watch 5:00 AM

Union County, South Dakota, United States

Last updated: 2:00 AM CDT  ·  Refresh
20°C
Feels like 20°
Rain
▲ 34°  /  ▼ 19°
Wind
11 mph E
Humidity
91%
Dew Point
19°
Pressure
28.53 inHg
Visibility
4 mi
UV Index
0.0
Cloud Cover
58%
Sunrise
6:52 AM
Sunset
7:59 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Union County is currently rain at 20°C. Precipitation is likely — peak probability 68% around 2 AM. Atmospheric instability is elevated (CAPE up to 1988 J/kg) — isolated convective development possible. Sunrise: 6:52AM · Sunset: 7:59PM.

Alerts

Severe Thunderstorm Watch
Expires 5:00 AM
Severe Thunderstorm Watch
Expires 5:00 AM
35 AQI · Good Dominant: O3 Air Quality
Hourly Forecast · Next 24 Hours
Now
20°
68%
3 AM
20°
24%
4 AM
19°
26%
5 AM
19°
14%
6 AM
17°
7%
7 AM
17°
4%
8 AM
19°
4%
9 AM
21°
4%
10 AM
22°
3%
11 AM
24°
3%
12 PM
26°
3%
1 PM
28°
3%
2 PM
31°
5%
3 PM
33°
8%
4 PM
34°
17%
5 PM
33°
18%
6 PM
34°
18%
7 PM
33°
21%
8 PM
31°
36%
9 PM
29°
27%
10 PM
26°
32%
11 PM
26°
32%
12 AM
24°
33%
1 AM
22°
36%
7-Day Forecast
Today
34° 19°
Mostly Clear with a 68% chance of rain.
Thu
38° 19°
Mostly Clear with a 36% chance of rain.
Fri
38° 22°
Mostly Clear with a 28% chance of rain.
Sat
38° 22°
Mostly Cloudy with a 56% chance of rain.
Sun
38° 21°
Rain, 64% chance.
Mon
38° 21°
Heavy Rain, 82% chance.
Tue
34° 18°
Drizzle, 53% chance.
TimeTempConditionsPrecipWindHumidity
Now 20° Rain 68% 11 mph E 91%
3 AM 20° Mostly Clear 24% 7 mph ESE 91%
4 AM 19° Mostly Clear 26% 7 mph ESE 91%
5 AM 19° Mostly Clear 14% 5 mph SE 93%
6 AM 17° Mostly Clear 7% 5 mph E 94%
7 AM 17° Mostly Clear 4% 4 mph E 95%
8 AM 19° Mostly Clear 4% 5 mph E 88%
9 AM 21° Mostly Clear 4% 6 mph ESE 80%
10 AM 22° Mostly Clear 3% 6 mph ESE 72%
11 AM 24° Clear 3% 6 mph SE 64%
12 PM 26° Clear 3% 6 mph SSE 56%
1 PM 28° Clear 3% 6 mph S 48%
2 PM 31° Clear 5% 7 mph S 44%
3 PM 33° Clear 8% 8 mph S 40%
4 PM 34° Clear 17% 9 mph S 38%
5 PM 33° Mostly Clear 18% 10 mph S 38%
6 PM 34° Mostly Clear 18% 9 mph S 39%
7 PM 33° Partly Cloudy 21% 9 mph S 42%
8 PM 31° Partly Cloudy 36% 8 mph S 50%
9 PM 29° Partly Cloudy 27% 7 mph SSE 57%
10 PM 26° Partly Cloudy 32% 7 mph SSE 64%
11 PM 26° Partly Cloudy 32% 6 mph SSE 68%
12 AM 24° Partly Cloudy 33% 6 mph SSE 72%
1 AM 22° Rain 36% 7 mph ESE 77%
15-Day Forecast
Today
9/2
Mostly Clear
68%
19°
34°
Thu
9/3
Mostly Clear
36%
19°
38°
Fri
9/4
Mostly Clear
28%
22°
38°
Sat
9/5
Mostly Cloudy
56%
22°
38°
Sun
9/6
Rain
64%
21°
38°
Mon
9/7
Heavy Rain
82%
21°
38°
Tue
9/8
Drizzle
53%
18°
34°
Wed
9/9
Drizzle
72%
14°
29°
Thu
9/10
Drizzle
44%
17°
30°
Fri
9/11
Drizzle
64%
15°
32°
Sat
9/12
Clear
60%
17°
31°
Sun
9/13
Drizzle
60%
16°
30°
Mon
9/14
Drizzle
60%
16°
29°
Tue
9/15
Drizzle
60%
16°
29°
Wed
9/16
Drizzle
60%
14°
28°
35
Good
U.S. Air Quality Index · Dominant: O3
50 100 150 200

Air quality is satisfactory and poses little or no health risk.

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
25 AQI 4.6 µg/m³
O3
Ground-level ozone
Dominant
35 AQI 39 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Today 35 Good 35 25
Thu 40 Good 40 26
Fri 40 Good 40 28
About the Air Quality Index
0–50 Good
51–100 Moderate
101–150 Unhealthy for Sensitive Groups
151–200 Unhealthy
201–300 Very Unhealthy
301–500 Hazardous

The U.S. AQI runs 0–500. The overall value equals the highest individual pollutant sub-index, and the dominant pollutant is the one driving it. PM2.5 (fine particles) is reported in µg/m³ and ozone (O3) in ppb. Forecast source: NWS NAQFC.

1000850700500400300250200150100 -40-30-20-10010203040 0.41247101624 LCLLFCEL0°C Temperature (°C) Pressure (hPa)
Temp Dewpoint Parcel (SB) CAPE CIN Dry adiabat Moist adiabat Mixing ratio
RAP
Valid Wed Sep 2, 05:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 50 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE31 J/kg
MLCAPE616 J/kg
MUCAPE2334 J/kg
SBCIN-427 J/kg
MLCIN-175 J/kg
Lifted Index-0.4
Kinematics
0–6 km Shear42 kt
0–1 km Shear14 kt
Eff. Shear36 kt
0–1 km SRH60
0–3 km SRH253
Eff. SRH233
Storm Motion280° @ 28 kt
0–1 km EHI0.0
Composite Parameters
Sig. Tornado0.0
STP (eff)0.1
Supercell10.1
K-Index43.0
Thermo & Levels
PWAT2.21 in
0–3 km LR3.9 °C/km
700–500 LR6.8 °C/km
Total Totals53.2
LCL946 hPa
LFC594 hPa
EL470 hPa
Freezing Lvl13,524 ft