Olean

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond this area.
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.

Flood insurance figures are for Cattaraugus County, the county that contains Olean.

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 in Cattaraugus County, the county that contains Olean.

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.

The drought index is for Cattaraugus County, the county that contains Olean.

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.

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 city centre.
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. Aug 9, 2009Flash Flood$45.0 million
   National Weather Service narrative

   A massive convective complex moved from lower Michigan across southern Ontario near Toronto then dove southeast across the Niagara Frontier and Western Southern Tier. This followed an earlier round of strong thunderstorms and heavy rains earlier in the day. Damage from the thunderstorm winds was widespread across the Niagara Frontier and Western Southern Tier. Trees as large as two to three feet in diameter were downed. Power outages were scattered throughout the region as the winds downed power lines.|The unprecedented heavy rains that fell���four to six inches in less than two hours���resulted in some of the worst flash flooding the area has seen. Parts of Erie,…

2. Nov 21, 2000Heavy Snow, Cattaraugus$10.0 million
   National Weather Service narrative

   Cold air crossing the warm waters of Lakes Erie and Ontario resulted in lake effect squalls that dropped over two feet downwind of the lakes.Off Lake Erie, the squall developed around midday on the 20th in a southwest flow ahead of a cold front. Snow fell at the rate of two to four inches per hour for several hours. The storm crippled much of the Buffalo metro area. Tens of thousands of people were stranded in autos as city and suburban streets became clogged with traffic and came to a standstill. Three thousand school children were stranded in buses which were unable to complete their routes. Snowfall in this early stage were as high as two feet in a narrow strip about three…

3. Jul 24, 2010Tornado$7.0 million
   National Weather Service narrative

   A NWS survey confirmed an EF2 tornado touched down.

4. May 13, 2014Flash Flood$5.0 million
   National Weather Service narrative

   A stalled warm front was the focus for heavy showers and embedded thunderstorms which trained across the western Southern tier. Rainfall amounts of one to three inches in just a few hours resulted in flash flooding across the region. Roads and culverts were washed out. Numerous roads were water-covered and closed. Some of these included: Routes 39, 62, and 353 in Gowanda; Route 242 in Little Valley; and Route 353 in Cattaraugus. Roads were also reported closed in Randolph, Derby, Evans Center, Salamanca, Perrysburg and Forestville. Evacuations took place in Silver Creek and Gowanda. In Gowanda, several high water rescues took place. States of Emergency were declared in Cattaraugus…

5. Jul 22, 2003Flash Flood$2.5 million
   National Weather Service narrative

   An upper low continued to produce thunderstorms across parts of the the western southern tier. Especially hard hit was the town of Angelica where a State of Emergency was declared. In addition to the downed trees and power lines, roads and basements were flooded. In Cattaraugus county, a car stalled in a flooded road and the driver had to be rescued. In Allegany State Park, the heavy rains and flash flooding resulted in evacuation of some camp areas.

6. Jan 19, 1996Flood, Cattaraugus$2.5 million
   National Weather Service narrative

   Rapid snowmelt of 1-2 feet of snow combined with heavy rainfall of over two inches to produce significant flooding. Nearly three hundred homes were damaged by flood waters. The Allegheny River caused major flooding and forced the evacuation of scores of people from their homes in Portville.

7. Jul 22, 2003Flash Flood$2.5 million
   National Weather Service narrative

   An upper low continued to produce thunderstorms across parts of the the western southern tier. Especially hard hit was the town of Angelica where a State of Emergency was declared. In addition to the downed trees and power lines, roads and basements were flooded. In Cattaraugus county, a car stalled in a flooded road and the driver had to be rescued. In Allegany State Park, the heavy rains and flash flooding resulted in evacuation of some camp areas.

8. Jun 26, 1998Flash Flood$2.5 million
   National Weather Service narrative

   Severe thunderstorms crossed the area during the early morning hours. The thunderstorms produced large hail and damaging winds which downed trees and power lines. The damage from thunderstorm winds paled in comparison to the damage resulting from the flash floods the thunderstorms produced. Five to six inches of rain fell in a two hundred square mile area sending small streams out of their banks causing several million dollars worth of property damage in the Villages of Arcade and Gowanda. Cattaraugus Creek rose faster than any time in memory and crested two feet over flood stage. This surge caused many boats to break loose from their moorings at the mouth of the creek at Sunset…

9. Jul 24, 2010Tornado$2.0 million
   National Weather Service narrative

   The thunderstorm which produced a tornado in Randolph continued moving east across Cattaraugus County and produced a second tornado which touched down in the Town of Carrollton at 549 pm EDT. The initial touchdown of the tornado occurred along Route 219 between Carrollton Village Road and Ismuth roads. The tornado continued east across mainly forested land producing significant tree damage until it entered the Village of Allegany. While the majority of the damage continued to be to trees and power poles, several homes did suffer damage from the tornado winds and from fallen trees. Final damage from the tornado occurred near the center of the village. A NWS survey concluded an EF1…

10. Jul 29, 2000Flash Flood$1.0 million
    National Weather Service narrative

    Torrential rains caused destructive flash flooding during the afternoon and evening hours. Over three inches of rain fell in less than a couple of hours. A mudslide closed portions of Interstate 86 (formerly Route 17) for several hours. Over forty basements were flooded. Roads were washed away including the Parkway Drive Extension.

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

101°FJul 9, 1936

All-time low

−35°FFeb 9, 1934

Warmest night

72°FJul 26, 1940

Coldest day

−3°F2 times, most recently Feb 16, 2015

Wettest day

4.00 inJun 18, 1984

Snowiest day

17.0 in2 times, most recently Jan 1, 1949

Hottest year

1949mean 48.6°F

Coldest year

1989mean 42.8°F

Wettest year

201757.38 in

Driest year

196031.11 in

Snowiest season

148.5 in2010-11

Station Allegany Sp (USC00300093), 1,500 ft elevation, 16.2 miles from the city centre. Daily records from 1924 to October 28, 2026; 91.4% 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.

Declarations for Cattaraugus County.

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.

• 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 USC00300093.
• 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.