riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Day County Disaster Risk

Day County, South Dakota

FEMA Risk Rating

Very Low

National Percentile

28th

of 3,144 counties

State Rank

#26

of 66 (1 = highest risk)

Flood Risk

20th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Very Low

Higher than 20% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 78% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 41% of US counties

Earthquake

Seismic activity and ground shaking risk

Very Low

Higher than 15% of US counties

Risk Overview

About Natural Disaster Risk in Day County, South Dakota

Day County risk slightly above state average

Day County's composite risk score of 27.64 exceeds South Dakota's 26.84 state average by less than one point, indicating risk exposure comparable to the statewide norm. Nationally, this "Very Low" rating reflects manageable but non-negligible disaster vulnerability.

Near-average risk among South Dakota counties

Day County ranks close to the median among South Dakota's 66 counties, with its 27.64 score placing it just slightly above statewide average exposure. This positioning suggests moderate but not exceptional natural disaster vulnerability relative to other counties in the state.

More exposed than most surrounding counties

Day County's 27.64 risk score significantly exceeds those of nearby Edmunds County (6.97) and Deuel County (6.87), making it one of the more vulnerable areas in the northeastern region. Davison County to the south presents comparable risk at 39.25, suggesting a broader vulnerability corridor.

Wildfire and tornado exposure dominate here

Wildfire risk reaches 77.86 in Day County—well above most state peers—making it the county's primary concern, while tornado risk of 40.62 poses secondary but significant threat. Flood risk remains moderate at 19.97, reflecting typical Great Plains precipitation patterns.

Prioritize wildfire and wind protection

Day County homeowners should ensure policies cover wind damage from tornadoes and obtain separate wildfire/brush fire coverage to address the county's elevated exposure. Review property defensibility around your home—clearing dead vegetation and maintaining clearance from structures significantly reduces loss severity.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Day County

Top Hazards by Exposure

  1. #1
    WildfirePrepare
    78th percentile
  2. #2
    TornadoPrepare
    41th percentile
  3. #3
    FloodPrepare
    20th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Risk Advisory: Day County

Risk Verdict

Day County carries a low natural disaster risk burden, scoring at the 28th percentile under the FEMA National Risk Index. At the 28th percentile, Day County's risk profile is among the more manageable in the country — the hazard-specific breakdown above shows where any remaining preparedness focus is best directed.

Hazard Breakdown

Wildfire risk is Day County's dominant natural hazard, ranked at the 78th percentile nationally under FEMA's National Risk Index. Tornado ranks second at the 41th percentile nationally. Additional tracked hazards include flood (20th percentile), earthquake (15th percentile).

Preparedness Context

Wildfire ranks as Day County's primary hazard at the 78th percentile nationally. For Day County households in high-WUI areas, go-bag readiness — the ability to leave within 15 minutes — is more important than shelter-in-place planning for most residential properties. A secondary tornado exposure at the 41th percentile nationally means Day County residents face hazards from two distinct natural peril categories during different seasons. Day County county's local emergency management office publishes community-specific wildfire risk assessments and evacuation zone maps; households should review their zone assignment and sign up for zone-specific alerts.

Regional Context

At 0.8 points from the South Dakota county mean, Day County's overall disaster risk profile is close to typical for this state, with no dramatic deviation in either direction.

Is your household prepared for Day County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Day County, SD?
Day County has a FEMA National Risk Index rating of Very Low, placing it in the 28th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect Day County?
Day County is evaluated for five major natural hazard types: wildfire (78th percentile), tornado (41th percentile), flooding (20th percentile), earthquake (15th percentile). The highest-risk hazard is wildfire at the 78th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does Day County risk compare to the South Dakota average?
Day County's composite risk percentile is 28th, compared to the South Dakota state average of 27th percentile. The state's overall risk rating is Very Low. This means Day County faces higher natural disaster risk than the typical county in South Dakota.
Is Day County at risk for wildfire?
Yes, Day County's wildfire risk is at the 78th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Day County is at the 20th percentile.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Why is Day County higher risk than average?
Day County's composite risk score of 28th percentile is above the South Dakota state average of 27th percentile. This elevated risk is driven by wildfire exposure (78th percentile). Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.
By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.