Franklin County, OH flood risk and hazards
FEMA rates none of the 7 reviewed hazards as Very High in Franklin County, OH. Modeled losses from natural hazards (expected annual loss) average about $331 million a year, for a population of 1,323,446. These county figures come from the FEMA National Risk Index, December 2025 release. Observation windows vary by metric and sit beside the tables below.
- Modeled expected annual loss
- $331.4 million / year
- US loss rank
- #65 of 3,232
- State loss rank
- #1 of 88
- Loss per resident
- $250 · state $259 · US $459
- FEMA overall risk rating
- Relatively High
Ohio county modeled loss
- Positive estimates to $10.6 million
- Above $10.6 million to $16.2 million
- Above $16.2 million to $22.1 million
- Above $22.1 million to $41.6 million
- Above $41.6 million to $331.4 million
- No FEMA estimate
Franklin County, OH ranks #1 of 88 in the state for modeled expected annual loss; the outline locates it.
View chart data
Is Franklin County at risk of flooding?
FEMA labels riverine flooding Relatively High and coastal flooding Not Applicable. Modeled annual riverine flood loss is $209,632,518; coastal flood loss is Not Applicable. These are separate hazards and county totals. A rating describes relative county risk. It does not locate water at a building or establish a flood zone. Read missing statuses using the source documentation. Keep both source labels when comparing counties. Read the county rating versus flood-zone guide before requesting a location check.
Look up an address and its flood zone through FEMA’s Flood Map Service Center.
The local hazard planning document is Franklin County Natural Hazards Mitigation Plan. Local governments use this plan to set out hazards and proposed projects.
What natural hazards affect Franklin County most?
Show tabular data
| County | Modeled expected annual loss (USD/year) | Overall risk rating |
|---|---|---|
| Franklin County, OH | 331,354,855.23 | Relatively High |
Show tabular data
| Hazard | Source label | Observation window |
|---|---|---|
| Coastal flooding | Not Applicable | 1996-2023 |
| Riverine flooding | Relatively High | 1996-2023 |
| Hurricane | Very Low | 1851-2024 |
| Wildfire | Very Low | 1996-2023 |
| Earthquake | Relatively Moderate | 1996-2023 |
| Tornado | Relatively High | 1950-2023 |
| Heat wave | Relatively High | 2005-2024 |
How have heat and rain changed in Franklin County?
Hot days
Hot days decreased between the two decades.
View chart data
| Place | Days / year |
|---|---|
| 1991–2000 | 1.20 |
| 2016–2025 | 0.70 |
Warm nights
Warm nights have the same mean in both decades.
View chart data
| Place | Days / year |
|---|---|
| 1991–2000 | 0.20 |
| 2016–2025 | 0.20 |
Heavy-precipitation days
Heavy-precipitation days increased between the two decades.
View chart data
| Place | Days / year |
|---|---|
| 1991–2000 | 0.00 |
| 2016–2025 | 0.10 |
Humid-heat days
Humid-heat days decreased between the two decades.
View chart data
| Place | Days / year |
|---|---|
| 1991–2000 | 0.90 |
| 2016–2025 | 0.20 |
| Measure | 1991–2000 | 2016–2025 | Change |
|---|---|---|---|
| Hot days · ≥35°C (95°F) | 1.2 | 0.7 | −0.5 |
| Humid-heat days · heat index ≥103°F (39.4°C) | 0.9 | 0.2 | −0.7 |
| Warm nights · ≥24°C (75.2°F) | 0.2 | 0.2 | 0.0 |
| Heavy-rain days · ≥50 mm (≈2 in) | 0.0 | 0.1 | +0.1 |
| Annual maximum daily precipitation · mm | 39.2 | 38.2 | −1.1 |
Counts are days per year; a grid-cell zero does not mean the county had no such events. Thresholds, time bases and limits: county climate method.
Methodology & sensor cross-check notes
Hot-day cross-check: NOAA’s county-average daily maximum temperature gives 1.3 → 0.8 hot days a year (−0.5); NASA gives 1.2 → 0.7 (−0.5). Both series show a decrease of the same rounded size, from different counts. The footprints differ, so agreement does not validate either count. Warm nights and precipitation were not cross-checked. Humid-heat row: Copernicus (ECMWF) reanalysis. It uses a different regional grid from the NASA measures.
No statistical significance, cause or future trend is established; this does not change the FEMA ratings above.
Climate data: NASA · Population context: US Census Bureau · Hot-day cross-check: NOAA county climate records · Humid heat: Copernicus (ECMWF). Method, sources and limitations · Climate JSON · Data credits.
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direction"}}How does El Niño affect Franklin County winters?
Strong El Niño winter precipitation
2 of 9 strong El Niño winters were wetter than normal. The vertical line marks 100% of normal precipitation.
View chart data
| Winter | Precipitation (% of normal) |
|---|---|
| 1957–58 | 85.985 |
| 1965–66 | 78.878 |
| 1972–73 | 80.065 |
| 1982–83 | 64.541 |
| 1991–92 | 79.367 |
| 1997–98 | 86.270 |
| 2009–10 | 81.921 |
| 2015–16 | 107.362 |
| 2023–24 | 105.577 |
NOAA and IRI both give 100% odds that El Niño conditions (tropical Pacific ONI of at least 0.5°C, not a local weather forecast) are present this winter. In Franklin County, 2 of 9 past strong El Niño winters were wetter than normal; the median winter had 82% of normal precipitation (rain and melted snow). The driest, 1982–83, had 65%.
| Winter | ONI | Precipitation | Temp. | Heavy days | Claims |
|---|---|---|---|---|---|
| 1957–58 | 1.7 | 86% | −0.2°F | 0 | — |
| 1965–66 | 1.6 | 79% | +0.4°F | 0 | — |
| 1972–73 | 1.8 | 80% | +2.0°F | 0 | — |
| 1982–83 | 2.1 | 65% | +4.6°F | 0 | 0 |
| 1991–92 | 1.5 | 79% | +3.4°F | 1 | 1 (#19) |
| 1997–98 | 2.4 | 86% | +5.8°F | 1 | 0 |
| 2009–10 | 1.5 | 82% | −4.0°F | 0 | 2 (#15) |
| 2015–16 | 2.6 | 107% | +3.7°F | 1 | 0 |
| 2023–24 | 2.0 | 106% | +4.9°F | 0 | 0 |
Winter normals and temperature baseline
Franklin County normals, 1990–91 to 2019–20 winters: 8.3 inches of precipitation (rain and melted snow) and 1.0 heavy days. Temperature is set against the county’s own winter trend of +0.5°F per decade since 1951–52.
Flood claims: December–February, from 1978 (— = before the data). The rank compares each winter with all 47 winters from 1978–79 to 2024–25 (#1 is the most claims; no rank is shown for 0 claims). The median winter had 1 claims; 1 of 6 strong winters in the data were above it. Insured exposure grew over time, so counts are not comparable across decades.
Past tendency is not a forecast and not a property-level finding. Before winter: four checks for property teams.
Sources: NOAA county climate records and Pacific climate assessments; FEMA National Flood Insurance Program claims. Method and limits · El Niño 2026–27.
What are the modeled losses by hazard?
From 1991–2000 to 2016–2025, hot days near Franklin County changed from 1.2 to 0.7 per year. Heavy-rain days changed from 0.0 to 0.1. The table retains humid heat, warm nights and maximum daily rain. Compare the periods alongside the source notes. These decade means describe past conditions; they do not predict a future year or establish a trend.
Franklin County’s modeled loss across all hazards is $331,354,855 per year. The FEMA National Risk Index ranks the hazards below by modeled loss, not rating category.
Show tabular data
| Hazard | Total loss ($/yr) | Of which buildings ($/yr) | Observation window |
|---|---|---|---|
| All hazards (composite) | $331,354,855 | $245,212,251 | 1996-2023 |
| Riverine flooding | $209,632,518 | $208,358,054 | 1996-2023 |
| Tornado | $29,005,557 | $19,028,088 | 1950-2023 |
| Heat wave | $25,244,251 | Not published | 2005-2024 |
| Earthquake | $9,501,027 | $6,782,327 | 1996-2023 |
| Hurricane | $73,096 | $68,874 | 1851-2024 |
| Wildfire | $13,434 | $11,675 | 1996-2023 |
| Coastal flooding | Not available | Not available | 1996-2023 |
These modeled county totals do not estimate property losses, insurance inputs or forecasts. Do not multiply them by location counts.
Reuse this chart
What is exposed in Franklin County?
Population and asset values show the scale behind county losses. These county totals are exposure measures, not loss figures.
Show tabular data
| Measure | Value | Observation window |
|---|---|---|
| Resident population | 1,323,446 | 2020-2020 |
| Building replacement value | $265,397,871,619 | 2020-2020 |
| Agricultural market value | $67,148,467 | 2022-2022 |
What do vulnerability and resilience show?
These relative rankings describe susceptibility to hazard impacts and capacity to recover. They measure no individual asset or outcome.
Show tabular data
| Measure | Score | Observation window |
|---|---|---|
| Social vulnerability index | 38.2 | 2020-2020 |
| Community resilience index | 65.3 | 2020-2020 |
Franklin County in the state and national rankings
National placement for Franklin County is #65 of 3,232, with an expected annual loss estimate of about $331.4 million. The county ranks #1 of 88 in Ohio and accounts for 10.8% of state loss. FEMA’s about $331.4 million figure describes a long-run average; actual annual loss can differ. Santa Cruz County, CA ranks immediately above it, with about $335.4 million in modeled annual loss. Middlesex County, MA ranks immediately below it, with about $321.9 million in modeled annual loss. Within the state list, Cuyahoga County, OH has the next lower estimate: about $282.4 million. Its 9.2% state loss share accompanies an estimate about $48.9 million away from this county’s total.
County hazard loss mix
Riverine Flood leads the modeled expected annual loss mix; bar lengths share a zero baseline.
View chart data
| Hazard | USD / year | Share |
|---|---|---|
| Riverine Flood | 209,632,518.38 | 63.3% |
| Cold Wave | 42,739,173.18 | 12.9% |
| Tornado | 29,005,557.02 | 8.8% |
| Heat Wave | 25,244,251.45 | 7.6% |
| Earthquake | 9,501,026.53 | 2.9% |
| Hail | 8,046,834.06 | 2.4% |
| Other | 7,185,494.60 | 2.2% |
National hazard loss ranks
Riverine Flood ranks #36 of 3,232 by modeled expected annual loss. Higher percentiles mean larger modeled losses.
View chart data
| Hazard | Rank | Percentile |
|---|---|---|
| Riverine Flood | #36 of 3,232 US · #1 of 88 in OH | 98.92 |
| Cold Wave | #26 of 3,232 US · #2 of 88 in OH | 99.23 |
| Tornado | #52 of 3,225 US · #3 of 88 in OH | 98.42 |
| Heat Wave | #31 of 3,202 US · #1 of 88 in OH | 99.06 |
| Earthquake | #232 of 3,232 US · #1 of 88 in OH | 92.85 |
| Hail | #53 of 3,225 US · #2 of 88 in OH | 98.39 |
Modeled loss per resident
Franklin has about $250 in modeled expected annual loss per resident. State and US values divide total loss by total population.
View chart data
| Place | USD / resident / year |
|---|---|
| Franklin | 250.37 |
| Ohio | 259.44 |
| US | 459.35 |
Franklin County hazard estimates
Riverine Flood
With about $209.6 million in modeled expected annual loss from riverine flooding, the county ranks #36 of 3,232 in the national comparison. In Ohio, this estimate ranks #1 of 88 and represents 63.3% of the county’s modeled loss; FEMA assigns a Relatively High rating; the Relatively High label covers 6 state counties and 186 nationally for riverine flooding.
Cold Wave
FEMA models about $42.7 million in expected annual loss from cold waves, placing the county #26 of 3,232 nationally. Its 12.9% share of total loss comes with a state loss rank of #2 of 88; FEMA assigns a Very High rating; the same rating for cold waves covers 2 Ohio counties and 39 across the US.
Tornado
For tornadoes, about $29.0 million in expected annual loss puts the county #52 of 3,225 across the US. This hazard makes up 8.8% of the total; FEMA assigns a Relatively High rating, and its loss ranks #3 of 88 in Ohio, matching 272 US counties, including 8 in Ohio, for this hazard.
Heat Wave
FEMA models about $25.2 million in expected annual loss from heat waves, placing the county #31 of 3,202 nationally. At 7.6% of the county’s modeled loss, the hazard places #1 of 88 statewide; FEMA assigns a Relatively High rating; for heat waves, 3 state counties and 98 US counties share that label.
Earthquake
The national loss rank for earthquakes is #232 of 3,232, based on about $9.5 million in modeled expected annual loss. At 2.9% of the county’s modeled loss, the hazard places #1 of 88 statewide; FEMA assigns a Relatively Moderate rating; for earthquakes, 3 state counties and 250 US counties share that label.
Hail
The national loss rank for hail is #53 of 3,225, based on about $8.0 million in modeled expected annual loss. Its 2.4% share of total loss comes with a state loss rank of #2 of 88; FEMA assigns a Relatively High rating, matching 166 US counties, including 7 in Ohio, for this hazard.
For riverine flooding, modeled loss is about $166.9 million above cold waves, leaving 50.4 percentage points between their county shares. Between cold waves and tornadoes, the modeled dollar gap is about $13.7 million; their shares differ by 4.1 percentage points. For tornadoes, modeled loss is about $3.8 million above heat waves, leaving 1.1 percentage points between their county shares. Between heat waves and earthquakes, the modeled dollar gap is about $15.7 million; their shares differ by 4.8 percentage points. The loss estimate for earthquakes exceeds hail by about $1.5 million, equivalent to 0.4 percentage points of total loss.
Population and recorded values
Franklin County covers about 549 square miles, with 1,323,446 residents in FEMA data. About $265.40 billion is the building value amount in FEMA’s record. The recorded agricultural value is about $67.1 million. Total modeled loss averages about $250 per resident annually, compared with about $259 statewide. The county holds 11.2% of the state population, compared with 10.8% of modeled loss. The county contains 9.9% of the building value recorded across Ohio. Among 88 state county records with both inputs, its density stands at position 1 from highest to lowest. The population-to-area ratio is about 2,410 residents per square mile; statewide it is about 260. At 1,323,446 residents, the county compares with the Ohio county median of about 58,530. In the US totals, the county represents 0.2% of modeled annual loss and 0.4% of recorded residents. The county’s about $250 per resident compares with about $459 nationally in modeled annual loss. About $324.2 million of annual loss falls within the six leading hazards, accounting for 97.8% of the total. The balance outside those six estimates is about $7.2 million, or 2.2% of total loss. The estimate for strong wind ranks #4 of 88 in Ohio: about $3.4 million annually, in local position 7. Nationally, this estimate places #140 of 3,225; its share of the county’s modeled loss is 1.0%. The estimate for lightning ranks #4 of 88 in Ohio: about $1.9 million annually, in local position 8. With 0.6% of county loss, this hazard has national placement #157 of 3,222.
FEMA labels and risk score
Franklin County has a FEMA risk index score of about 98.1, ranking #62 of 3,144 nationally. FEMA labels risk index as Relatively High, matching 3 county records across Ohio. FEMA labels expected annual loss as Relatively High, matching 3 county records across Ohio. For social vulnerability, FEMA assigns Relatively Low; 24 counties in Ohio have that label. The community resilience rating is Relatively High, a label shared by 21 of 88 Ohio counties. Within Ohio, the risk score places #1 of 88 and the dollar loss places #1 of 88. Within Ohio, 7 counties share both labels: Relatively Low vulnerability and Relatively High resilience. This county accounts for 61.6% of that group’s annual loss, while the group accounts for 17.6% across Ohio. On the state risk-score list, Cuyahoga County, OH sits immediately below, scoring about 98.0 and ranking #2 of 88. For that neighboring score, the risk index category is Relatively High, and the county’s state loss share is 9.2%. Nationally, 632 counties carry the same Relatively Low social vulnerability label, covering 30.0% of FEMA’s recorded population. Nationally, 629 counties carry the same Relatively High community resilience label, covering 24.5% of FEMA’s recorded population. Across the county’s hazard ratings, 1 carry Very High: cold waves. The county’s Relatively High group contains 8 hazards: hail, heat waves, ice storms, lightning, riverine flooding, strong wind, tornadoes, winter weather. The county’s Relatively Moderate group contains 1 hazard: earthquakes. The county’s Relatively Low group contains 2 hazards: drought, landslides. The county’s Very Low group contains 2 hazards: hurricanes, wildfires.
What else should I know about Franklin County?
What is modeled loss per resident in Franklin County?
Franklin County averages about $250 per resident in modeled annual loss.
What does FEMA estimate for tornadoes in Franklin County?
Franklin County has about $29.0 million in modeled expected annual loss from tornadoes, with a Relatively High rating.
What is the FEMA risk index rating for Franklin County?
FEMA assigns Franklin County a Relatively High risk index rating.
Where does Franklin County rank within Ohio?
Franklin County ranks #1 of 88 for modeled expected annual loss.
What does FEMA estimate for riverine flooding in Franklin County?
For riverine flooding, FEMA lists Franklin County at Relatively High, with about $209.6 million in modeled expected annual loss.
What does FEMA estimate for earthquakes in Franklin County?
For earthquakes, FEMA lists Franklin County at Relatively Moderate, with about $9.5 million in modeled expected annual loss.
Which strong El Niño winter had the most flood claims in Franklin County?
Franklin County recorded 2 December–February NFIP claims in 2009–10, ranked #15 among 47 winters.
Where next for Franklin County?
See how the county compares across the state in Ohio natural hazard risk by county, download the FEMA county hazard data, or review the county climate risk data API and bulk files. Check the sources and what each measure can show on the methodology page.