Mercer County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Mercer County: 9.
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.

Every storm within 100 miles

1. Tropical storms and hurricanes (34 kt or more, still tropical) at closest approach. Post-tropical remnants with gale-force winds are listed but not counted. Direct: track within 50 miles; near: within 100 miles. Distance is measured to the county boundary for counties and to the city centre for cities, using positions interpolated hourly between HURDAT2 fixes.

National Hurricane Center HURDAT2, 1851 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. Nov 10, 2002Tornado$1.0 million
   National Weather Service narrative

   Starting about 7:54 PM, an F2 tornado touched down near Trout Island Road, east of Sharpsville. The tornado traveled northeast at 50 mph, crossed Route 18, then ripped into Clark. It crossed Shenango River Lake and tracked to New Hamburg, where it dissipated 8:02 PM. The tornado path was 7 miles long, about 500 yards wide at its maximum, in the town of Clark. Maximum winds estimated 155 mph. Majority of damage and all injuries occurred in Clark. Fifteen homes completely destroyed, 13 major damage, 29 had minor damage. One business destroyed; 1 suffered major damage. A large number of trees were snapped or toppled. Large truck was overturned. One van was thrown across Route 258.…

2. Sep 14, 2008High Wind, Mercer$1.0 million
   National Weather Service narrative

   Low pressure from the remains of Hurricane Ike moved across central Ohio to Lake Erie on the evening of September 14th and produced very strong winds into the early morning of September 15th across eastern Ohio, northern West Virginia, and western Pennsylvania. Widespread damage to trees and power lines was reported across the region with power outages and damage to some structures from falling trees. Power was not restored to some rural areas for one week after the storm. At the peak of the storm more than 2 million homes were without power. For a period of about 8 hours, sustained winds during the storm were from 30 to 50 MPH, with gusts well over 60 MPH. The highest reported…

3. Oct 6, 2024Thunderstorm Wind$1.0 million
   National Weather Service narrative

   There was a tree reported down along Fullington Road.

4. Apr 28, 2002Tornado$750,000
   National Weather Service narrative

   A storm producing two separate tornadoes moved across Mercer and Venango counties. The first tornado spawned by this storm, an F0, touched down in Mercer County at 1:35 PM EST near the community of Hermitage (approximately 2 miles east of Sharon) and moved to the east-northeast for about 6 miles before dissipating at approximately 1:40 PM EST. The maximum estimated winds were about 70 MPH. Some of the damage observed from this first tornado included a downed fire tower near Hermitage. The windward side of a barn in Jefferson Township was blown apart and the adjacent building exhibited large holes in the metal sides from flying debris. A garage that was under construction also…

5. Dec 20, 2004Heavy Snow, Mercer$650,000
   National Weather Service narrative

   Another round of lake effect snow began in the early morning of the 19th. Farming (Fayette Co) reported 6" of snow by 10 PM on 19th. Sharon had 4 inches by 10 PM on 19th, and 6" by midnight. In Mercer Co, near Hermitage, on Interstate 80, snow covered roads caused an 80-car accident 1130 AM on 19th. 100 people were injured, 3 seriously.

6. Aug 16, 2002Flash Flood$250,000
   National Weather Service narrative

   Heavy thunderstorm rains of over 3 inches in only a few hours resulted in numerous reports of flooding across the downtown Sharon area. Several businesses reported flood damage. A 50-by-60 foot section of the roof of one business collapsed due to the weight of the rain water. Many homes reported flooded basements, while one home had its basement wall collapsed by the rushing waters. Several roadways across the Sharon area were impassible due to flooding.

7. Sep 8, 2004Flood, Mercer$200,000
   National Weather Service narrative

   At 730 PM EDT on 8th, State Rte 258 was closed by flood near Mercer. As of 9 AM on 9th, widespread flooding continued. At Jamestown, 12 families were evacuated as a precaution because of a dam (time unknown); the dam did not fail. Total rain: 4 inches in Mercer. There was a record flood on the Shenango River at Transfer, which crested at 10.65 ft at 11 AM EDT on 9th (previous record 10.47). (FRANCES)

8. Apr 28, 2002Tornado$150,000
   National Weather Service narrative

   A storm producing two separate tornadoes moved across Mercer and Venango counties. The first tornado spawned by this storm, an F0, touched down in Mercer County at 1:35 PM EST near the community of Hermitage (approximately 2 miles east of Sharon) and moved to the east-northeast for about 6 miles before dissipating at approximately 1:40 PM EST. The maximum estimated winds were about 70 MPH. Some of the damage observed from this first tornado included a downed fire tower near Hermitage. The windward side of a barn in Jefferson Township was blown apart and the adjacent building exhibited large holes in the metal sides from flying debris. A garage that was under construction also…

9. Nov 15, 2020Thunderstorm Wind$100,000
   National Weather Service narrative

   Numerous reports of wind damage were received from across the county.

10. Jul 8, 2014Thunderstorm Wind$100,000
    National Weather Service narrative

    A NWS Storm Survey found damage from a micro-burst along a 1.4 mile long path along U.S. Highway 62 in Jackson Center. The maximum winds were estimated between 80 and 85 MPH, and the width of the damage path was around 50 yards. Damage consisted of numerous soft and hardwood trees snapped or uprooted, with roof damage to several family homes and garages.

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

103°FJul 10, 1936

All-time low

−22°FJan 19, 1994

Warmest night

81°FAug 17, 1938

Coldest day

−6°FJan 19, 1994

Wettest day

4.65 inJul 21, 2003

Snowiest day

17.2 inJan 24, 1948

Hottest year

2024mean 53.4°F

Coldest year

1980mean 46.2°F

Wettest year

201154.01 in

Driest year

196323.79 in

Snowiest season

118.7 in2010-11

Station Youngstown-warren Regional Airport (USW00014852), 1,167 ft elevation, 17.5 miles from the population centre. Daily records from 1934 to October 26, 2026; 99.9% 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 USW00014852.
• 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.