Union County, SD Environment & Hazard Risk

• WildfireRelatively Low$447K/yr expected annual loss, about once every 1,048 years
• Winter weatherRelatively Moderate$256K/yr expected annual loss, about 15 events a year
• DroughtRelatively Moderate$951K/yr expected annual loss, about 27 events a year
• HailRelatively Moderate$917K/yr expected annual loss, about 6.5 events a year
• TornadoRelatively Moderate$3.44M/yr expected annual loss, about once every 3 years
• Ice stormRelatively Moderate$272K/yr expected annual loss, about once every 1 year
• LandslideVery Low$670/yr expected annual loss, about once every 13 years
• Cold waveRelatively Low$734K/yr expected annual loss, about 6.5 events a year
• Heat waveVery Low$234K/yr expected annual loss, about 6.5 events a year
• LightningRelatively Low$164K/yr expected annual loss, about 40 events a year
• Strong windRelatively Low$346K/yr expected annual loss, about 4.1 events a year
• EarthquakeVery Low$27.95K/yr expected annual loss, about once every 2,000 years

Bars show the national percentile score (0 to 100) for each hazard. Dollar figures are expected annual losses to buildings, people and crops. Not rated here: avalanche, coastal flooding, hurricane, riverine flooding, tsunami, volcanic activity.

Check the flood zone for an address

Homes with flood insurance

199 of 7,883 (2.5%)

Homes in high-risk flood zones

208

Insured in high-risk zones

54 (26%)

Flood claims since 1978

443

Claims paid since 1978

$7.56M

• Flood141
• Hail140
• Thunderstorm Wind123
• Winter Weather92
• Drought65
• High Wind43
• Winter Storm33
• Blizzard26 · 1 death
• Excessive Heat21
• Flash Flood19

• Flood06/21/2024

  Elk PT, Union County

  $54.52M damage

  What happened

  Rainfall amounts across Union County from June 20-22 ranged from around a third of an inch across southern areas to 1 to 2 inches across northern areas. Farther north and upstream, 6 to 10 inches of rain fell across portions of southeast South Dakota and northwest Iowa, with locally higher amounts in excess of 12 inches. ||This rainfall resulted in record flooding along the Big Sioux River and extensive overland flooding along the adjoining flood plain. County-wide, 44 residences were destroyed and another 182 received minor to major flood damage. Estimated losses exceed 52 million dollars. At the peak of the flooding, there were an estimated 20 to 30 water rescues. ||Residents along Northshore and Penrose Drives on the north side of McCook Lake were evacuated on the evening of June 23 as flood waters rose rapidly. Catastrophic damage ensued, with at least 26 homes declared a total loss and nearby infrastructure destroyed. Interstate 29 was inundated with water north of North Sioux City and closed June 23. The road reopened two days later on June 25. The railroad bridge crossing the Big Sioux River at North Sioux City also collapsed due to flooding. ||Preliminary damage...

• Blizzard01/15/2021

  Union

  1 death, 2 injured

  What happened

  As snow redeveloped and began to accumulate toward evening on January 14, the increase in winds to a sustained 30 to 40 mph with a few gusts as high as 62 mph at South Dakota RWIS site 3 miles south of Beresford and 55 mph near North Sioux City, resulted in widespread near white-out conditions. Interstate 29 was closed in South Dakota at 2200CST January 14 and reopened at 0630CST January 15. Snowfall totaled 2.2 inches 6 miles north northeast of Elk Point. At 1820CST on January 15, a two vehicle accident 2 miles south of Elk Point resulted in the indirect fatality to the driver of a southbound pickup which slid through the median and collided with an oncoming SUV in the northbound lane. Two occupants in the other vehicle suffered indirect injury.

• Flood06/01/2019

  Elk PT, Union County

  $11.48M damage

  What happened

  During crop planting season, prolonged flooding led to the loss of or inability to plant crops across the area. Crop loss estimates provided by the United States Department of Agriculture.

• Drought07/01/2022

  Union

  $11.31M damage

  What happened

  Extreme (D3) drought conditions remained in place through July, which featured temperatures of 2 to 3 degrees above normal and 50 to 75 percent of normal precipitation. Crop damage is an estimate from insured losses. Information provided by the United States Department of Agriculture.

• Winter Weather03/20/2020

  Union

  11 injured

  What happened

  Rain changed quickly to snowfall late afternoon on March 19, with visibility to around one-half mile at times between 1700-2100CST. The intense snowfall rate made travel hazardous during the late afternoon and early evening as winds increased to a peak of 47 mph 3 miles south of Beresford. Snowfall totaled 2.0 inches 6 miles north northeast of Elk Point. Around 0735CST on March 20, a northbound bus attempted to change lanes on snow-covered Interstate 29 5 miles south of Elk Point, lost control, and overturned in the east ditch. 11 passengers were (indirectly) injured.

• Drought08/01/2022

  Union

  $6.85M damage

  What happened

  Extreme (D3) drought conditions persisted through August. Temperatures were around 2 to 3 degrees above normal, with precipitation generally 60 to 75 percent of normal, but locally up to 50 percent above normal near the Missouri River. Crop damage is an estimate from insured losses. Information provided by the United States Department of Agriculture.

• Excessive Heat07/20/2026

  Union

• Thunderstorm Wind53 kt wind07/01/2026

  Alcester, Union County

• Drought07/01/2026

  Union

• Excessive Heat06/29/2026

  Union

• Drought06/01/2026

  Union

• Hail1" hail06/01/2026

  Big Spgs, Union County

• Hail0.88" hail05/19/2026

  Elk PT, Union County

• Drought05/01/2026

  Union

• South Lincoln Rural Water SystemServes 5,250 · Groundwater · PrivateNo health violations+2 monitoring or reporting
• Clay Rural Water SystemServes 4,780 · Groundwater · PrivateNo health violations
• Dakota Dunes CidServes 3,700 · Purchased groundwater · Local governmentNo health violations
• North Sioux CityServes 3,042 · Groundwater · Local governmentNo health violations
• BeresfordServes 2,359 · Purchased groundwater · Local governmentNo health violations
• Elk PointServes 2,124 · Groundwater · Local governmentNo health violations
• Clay Rws/South UnionServes 1,447 · Groundwater · PrivateNo health violations
• AlcesterServes 820 · Purchased groundwater · Local governmentNo health violations+4 monitoring or reporting