Yankton County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Yankton County: 0.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

More event types since 1996

Costliest events since 1996

1. Apr 1, 2019Flood$20.0 million
   National Weather Service narrative

   Continued precipitation with high water levels damaged county and township roadways during April. 260 miles of gravel roads were reported completely unusable at times during the month.

2. Mar 13, 2019Flood$9.8 million
   National Weather Service narrative

   Street flooding in numerous intersections within the city of Yankton. A high number of flooded basements also reported, especially along Marne Creek. Other flooding resulted in extensive damage to public infrastructure including numerous county and township roads, culverts, and some bridges.

3. Jul 9, 2009Hail$5.0 million
   National Weather Service narrative

   Large hail, accompanied in places by damaging winds, destroyed or severely damaged crops in an area up to 10 miles wide from northwestern to southeastern Yankton County. Estimates from the Farm Service Agency were at least 48 thousand acres of corn, soybean, and alfalfa crops that were affected, some of which were totally destroyed. The hail also broke windows in buildings and vehicles, severely dented and even punched holes in numerous vehicles, and damaged siding and roofs of buildings. Property damage was especially great in and near the cities of Yankton and Gayville. Most of about 200 skylights in a Wal-Mart store in Yankton were broken beyond repair. Some of the windows in…

4. Jul 9, 2009Hail$3.0 million
   National Weather Service narrative

   Large hail broke windows, damaged vehicles, and damaged trees.

5. Aug 18, 2011Hail$2.0 million
   National Weather Service narrative

   Large hail up to golf ball size, driven by strong to damaging winds, caused widespread property and crop damage in and near Yankton. Numerous windows were broken, both in structures and in vehicles, roofs and siding were damaged in several homes and businesses, and trees were stripped. Corn and other crops in the area were heavily damaged, with crops totally stripped in some areas. The amount of crop damage could not yet be determined.

6. Sep 1, 2019Flood$1.5 million
   National Weather Service narrative

   Flooding continued from August, but the James River near Yankton (YNNS2) soon fell below flood stage on September 4. However, excessive rainfall of 4 to 8 inches upstream September 10-12 (7.54 inches at Mitchell and 7.21 inches 7 miles south of Parkston) led to a rapid rise and a record crest 15.1 feet above flood stage on September 14. Five of the six bridges crossing the James River in Yankton county were closed. Innumerable roads were inundated and closed for several days, including major roadways of Highway 81 north of Yankton and Highway 46 west of Irene. Extensive amounts of agricultural land were inundated. Fifty-five homes were impacted by flood waters in Yankton county,…

7. Apr 1, 2011Flood$1.0 million
   National Weather Service narrative

   Major flooding of the James River, as well as flooding of small streams and lakes in the county, continued through April. Much farmland remained flooded, both near to and away from the James River. The James River was 9.2 feet above flood stage near Yankton April 1st, and fell very slowly during the month. A large area of land and numerous roads were flooded at the start of the month. Water was running over other roads, from flooded streams, creeks, and fields as well as from the James River. Many roads were heavily damaged. Some homes and businesses were also flooded, with the flooding of these places slowly alleviating through the month. High water and groundwater levels from…

8. Jul 9, 2009Hail$500,000
   National Weather Service narrative

   Large hail damaged vehicles and broke windows. The hail was accompanied by wind gusts up to 50 mph.

9. Aug 18, 2011Thunderstorm Wind$500,000
   National Weather Service narrative

   Thunderstorm winds caused widespread tree damage, including numerous trees blown down. Some homes were damaged by falling trees or tree debris. The winds drove hail that was up to golf ball size, and with the hail contributed to crop damage in the area.

10. Jun 21, 2024Flood$227,000
    National Weather Service narrative

    Rainfall amounts across Yankton County from June 20-22 ranged from 1 to 3 inches. Farther north and upstream, 5 to 10 inches of rain fell across portions of southeast South Dakota. This rainfall resulted in major flooding along the James River and extensive overland flooding along the adjoining flood plain. Some overland flooding also occurred along Clay Creek and the Marindahl Lake area. ||Multiple county roads succumbed to flood waters and were closed with some damages reported. Preliminary damage assessments estimate loss to public infrastructure to be nearly 227 thousand dollars. ||For additional information on river flooding, please see other flood entries for Yankton County.

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

110°FJun 22, 1988

All-time low

−31°FDec 23, 1989

Warmest night

82°FAug 17, 1988

Coldest day

−19°FDec 22, 1989

Wettest day

4.20 inJun 17, 1990

Snowiest day

16.0 inJan 20, 1988

Hottest year

1987mean 51.8°F

Coldest year

1951mean 43.9°F

Wettest year

201843.10 in

Driest year

195613.00 in

Snowiest season

70.5 in2015-16

Station Yankton 2 E (USC00399502), 1,172 ft elevation, 2.3 miles from the population centre. Daily records from 1948 to October 21, 2026; 96.1% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00399502.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.