NHC HURDAT2 · SPC Tornado Database
Hurricanes and Tornadoes That Hit Mercer, PA
Every tropical system within 75 miles since 1851 and every tornado within 25 miles since 1950.
Data: NOAA NHC HURDAT2 and NOAA SPC tornado and hail reports, through 2025 · Updated
10 tropical systems have passed within 75 miles of Mercer, Pennsylvania since 1851, 0 of them at hurricane strength; the most recent was Sandy in 2012. Since 1950, 71 tornadoes have touched down within 25 miles, 5 of them rated EF3 or stronger.
- Hurricanes
- 0
- Tropical storms
- 10
- Tornadoes
- 71
- EF3 or stronger
- 5
within 75 mi, since 1851
below hurricane strength
within 25 mi, since 1950
38 deaths in all
What the records show for Mercer
None of the 10 tropical systems was at hurricane strength as it passed Mercer; the strongest was an unnamed storm in 1896, a tropical storm with 60 mph winds when its centre passed 71 miles away. The record near Mercer begins with an unnamed storm in 1878; the most recent system was Sandy in 2012, a tropical storm 8 miles away. Of the 10 systems, 2 have come since 2000. Of the 794 Pennsylvania cities on this site, 73% have more tropical storms and hurricanes within 75 miles than Mercer. The strongest of the 71 tornadoes within 25 miles was an F5 on May 31, 1985; its path came within 2 miles, and it killed 18 people. Of the 71, 6 had paths within 5 miles of the city centre, and 29 have come since 2000. July has had the most tornadoes, 15. The most recent tornado was on May 21, 2025. Mercer has more tornadoes within 25 miles than 68% of the 794 Pennsylvania cities. Hail has been reported within 10 miles 76 times since 1956, with stones up to 2.25 inches. Mercer has more hail reports within 10 miles than 73% of the 794 Pennsylvania cities.
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Tropical storms and hurricanes near Mercer
| Year | Storm | Closest | Strength when closest | Peak |
|---|---|---|---|---|
| 2012 | SandyOct 31 | 8 mi | Tropical storm (39 mph) | Category 3 |
| 2003 | IsabelSep 19 | 7 mi | Tropical storm (39 mph) | Category 5 |
| 1995 | OpalOct 6 | 46 mi | Tropical storm (46 mph) | Category 4 |
| 1989 | HugoSep 22 | 19 mi | Tropical storm (41 mph) | Category 5 |
| 1955 | ConnieAug 14 | 65 mi | Tropical storm (51 mph) | Category 4 |
| 1928 | Unnamed 1928 stormSep 20 | 67 mi | Tropical storm (40 mph) | Category 5 |
| 1915 | Unnamed 1915 stormOct 1 | 75 mi | Tropical storm (40 mph) | Category 4 |
| 1902 | Unnamed 1902 stormJun 29 | 29 mi | Tropical storm (40 mph) | Category 1 |
| 1896 | Unnamed 1896 stormSep 30 | 71 mi | Tropical storm (60 mph) | Category 3 |
| 1878 | Unnamed 1878 stormSep 13 | 62 mi | Tropical storm (47 mph) | Category 2 |
Strength is the sustained wind on the track at the closest point, which is not the wind felt in Mercer: a hurricane's worst winds sit within a few dozen miles of its centre, and inland cities are usually past that.
Tornadoes within 25 miles of Mercer
By decade
- 2020s5
- 2010s11
- 2000s13
- 1990s14
- 1980s12(2 EF3+)
- 1970s8(1 EF3+)
- 1960s2
- 1950s6(2 EF3+)
| Date | Rating | Distance | Path | Killed / injured |
|---|---|---|---|---|
| May 31, 1985 | F5 | 2 mi | 47 mi | 18 / 310 |
| May 31, 1985 | F4 | 16 mi | 56.2 mi | 16 / 125 |
| Aug 5, 1956 | F3 | 24 mi | 0.1 mi | 2 / 0 |
| Mar 1, 1955 | F3 | 23 mi | 2.5 mi | 1 / 6 |
| May 2, 1972 | F3 | 16 mi | 7.9 mi | 0 / 3 |
| Nov 10, 2002 | F2 | 9 mi | 7 mi | 1 / 19 |
| May 25, 2004 | F2 | 21 mi | 7 mi | 0 / 0 |
| Apr 9, 2001 | F2 | 21 mi | 4 mi | 0 / 0 |
| Aug 8, 1992 | F2 | 13 mi | 2 mi | 0 / 0 |
| Aug 8, 1992 | F2 | 16 mi | 1.5 mi | 0 / 11 |
| Jun 27, 1987 | F2 | 24 mi | 1.5 mi | 0 / 0 |
| Oct 3, 1986 | F2 | 7 mi | 9 mi | 0 / 0 |
The strongest 12 of 71, by rating and then by deaths. Ratings before February 2007 are on the original Fujita scale.
Hail in Mercer
The Storm Prediction Center has 76 hail reports within 10 miles of Mercer since 1956, made on 40 separate days. Of these, 51 were 1 inch across or larger, and 3 reached 2 inches. The largest, 2.25 inches, fell on May 28, 2019. The most recent report is from October 6, 2024. April and May have the most reports, 18 each.
Source: NOAA Storm Prediction Center severe weather reports, data through 2025.
Weather by month in Mercer
The nearest NOAA station with 1991–2020 climate normals is Slippery Rock 1 SSW, PA, 15 miles southeast of Mercer at 1,260 feet. July is the warmest, with an average high of 81°F and low of 58°F; January is the coolest, at 33°F and 17°F. June is the wettest at 4.8 inches of precipitation on average and February the driest at 2.7 inches; the year adds up to 45.3 inches over 96 days with at least a tenth of an inch. June to November, the hurricane season months, bring 54% of the year's precipitation (24.5 of 45.3 inches); the other six months are drier. September has brought the most of the 10 tropical systems that passed within 75 miles (5); a normal September there has highs of 74°F and 4.1 inches of precipitation. Highs reach 90°F on about 13 days a year, almost all from June to September. Lows fall below freezing on about 142 nights a year. That 45.3 inches is more than at 84 of the 148 Pennsylvania stations used on this site (57%). New Wilmington, 9 miles southwest, has its own station (New Castle 1 N, PA): 42.0 inches a year, 3.3 less than here, and a July average high of 86°F against 81°F.
| Month | High °F | Low °F | Precip. in | Days ≥ 0.1" |
|---|---|---|---|---|
| Jan | 33 | 17 | 3.5 | 8 |
| Feb | 37 | 18 | 2.7 | 7 |
| Mar | 46 | 25 | 3.4 | 8 |
| Apr | 59 | 35 | 3.9 | 9 |
| May | 69 | 45 | 4.1 | 9 |
| Jun | 77 | 54 | 4.8 | 9 |
| Jul | 81 | 58 | 4.6 | 9 |
| Aug | 80 | 56 | 4.0 | 7 |
| Sep | 74 | 50 | 4.1 | 7 |
| Oct | 62 | 39 | 3.5 | 8 |
| Nov | 49 | 31 | 3.5 | 8 |
| Dec | 38 | 23 | 3.2 | 8 |
| Year | 59 | 38 | 45.3 | 96 |
Averages for 1991–2020 at Slippery Rock 1 SSW, PA (1,260 ft), from NOAA NCEI U.S. Climate Normals. Normals describe the station; the farther a place is from it, and the bigger the difference in height, the more its weather can differ.
Floods, thunderstorm wind and lightning near Mercer
Since 1996, the National Weather Service has logged 204 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Mercer: 185 thunderstorm wind reports, 12 flash floods, 6 floods and 1 heavy rain event. They killed 0 people and injured 1, and the NWS estimated $3.2 million in property and crop damage. The strongest thunderstorm gust on record here was 83 mph, on July 8, 2014. July has had the most flash floods, 4 of 12. Of the 788 Pennsylvania cities on this site with a flash flood on record, 211 have had fewer than Mercer.
July 17, 2010: thunderstorm wind 8 miles from the centre of Mercer — 1 injured, $25,000 damage.
October 6, 2024: thunderstorm wind 4 miles from the centre of Mercer — $1.0 million damage.
NWS: “There was a tree reported down along Fullington Road.”
July 17, 2010: thunderstorm wind 9 miles from the centre of Mercer — $100,000 damage.
Source: NOAA NCEI Storm Events Database, events whose starting point is on record, 1996 to June 30, 2026. Damage is the NWS estimate in the dollars of the year, not insured losses, and NWS notes that some reports are unverified.
Flood insurance claims, disaster declarations and FEMA risk ratings
Mercer County, which includes Mercer, has been named in 13 federal disaster or emergency declarations since 1972, 8 of them major disasters (by incident: 3 floods, 3 hurricanes, 2 biological emergencies, 2 severe storms). The latest major disaster declaration was Covid-19 Pandemic, on March 30, 2020. FEMA's National Risk Index gives Mercer County a Relatively Low rating for natural hazard risk overall; by hazard: Relatively High for lightning; Relatively Moderate for hail, inland flooding and strong wind; Relatively Low for hurricanes and tornadoes; Very Low for heat waves. It models the county's expected loss from all 18 hazards it covers at $34.1 million a year, the 28th highest of 67 Pennsylvania counties; of the hazards above, the largest share, $29.1 million (85%), is from inland flooding.
Claims: FEMA, OpenFEMA Dataset FIMA NFIP Redacted Claims – v3, summed over ZIP codes; payments in the dollars of each year, not adjusted for inflation. Declarations: Disaster Declarations Summaries – v2, by county. Retrieved October 25, 2026. 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).
Risk ratings: FEMA, National Risk Index county table, December 2025 (v1.20), retrieved October 26, 2026; ratings compare counties nationwide, are meant for planning and are no substitute for a local risk assessment. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets 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).
What counts as a pass, the distances and the sources: how this storm history is built.
Cities near Mercer
- New Wilmington, PA9 mi
- Grove City, PA9 mi
- Volant, PA9 mi
- Stoneboro, PA10 mi
- Hermitage, PA12 mi
- Transfer, PA12 mi
- Sharpsville, PA12 mi
- West Middlesex, PA12 mi
- Sandy Lake, PA13 mi
- Farrell, PA13 mi
- Sharon, PA14 mi
- Greenville, PA14 mi
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