Blair County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Blair County: 0.
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.

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.

Costliest events since 1996

1. Nov 8, 2024Wildfire, Blair$2.0 million
   National Weather Service narrative

   A wildfire developed during the afternoon of November 8, 2024 in Frankstown Township near Canoe Creek State Park in Blair County. The wildfire occurred during a stretch of unseasonably warm and dry weather along with gusty winds, and it quickly expanded in size to around 300 acres. At the fire's peak, aerial support was enlisted to battle the fire, along with firefighting crews on the ground. Winds began to decrease during the late morning hours of November 10th with scattered rain showers assisting firefighters in putting out the blaze by the late afternoon and evening hours. While attempting to put the wildfire out, three firefighters sustained minor injuries.

2. Aug 9, 2003Flash Flood$250,000
   National Weather Service narrative

   Significant Flash Flooding occurred in the Altoona and Hollidaysburg areas from torrential thunderstorm rains. Route 36 and Route 764 were closed due to flooding. One bridge on 14th street sustained damage to the road surface. Two families were displaced from their homes after flood waters collapsed the basements of their homes. In all, 4 homes suffered major flood damage while about 200 homes had flooded basements. In addition, six townhouses had water on the first floor. The American Red Cross provided housing for the residents in Frankstown Township.

3. Feb 12, 2009High Wind, Blair$100,000
   National Weather Service narrative

   Non-thunderstorm wind gusts between 55 and 65 mph toppled numerous trees and power lines across Blair County. The high winds ripped a roof off of a school and caused severe damage to an adjacent church in Duncansville. Downed trees closed roads in the city of Altoona, where high wind damage was rather extensive based on insurance claims. Some residents were without power for several days.

4. Mar 16, 2025Thunderstorm Wind$80,000
   National Weather Service narrative

   An NWS Storm Survey confirmed a downburst in Scotch Valley on March 16, 2025 as a line of severe thunderstorms moved through. Maximum winds were estimated at 100 mph with damage occurring along a 4.5 mile long path. Dozens of trees were uprooted or snapped along Scotch Valley Road and porch roofs were blown off. Significant structural damage to a barn was also reported. The damage path widened to around 1.6 miles as it neared the end of the track.

5. Aug 19, 2017Thunderstorm Wind$50,000
   National Weather Service narrative

   A severe thunderstorm producing winds estimated near 60 mph knocked down a barb that was built in 1870.

6. Apr 29, 2025Thunderstorm Wind$50,000
   National Weather Service narrative

   A line of severe thunderstorms producing wind gusts estimated at 70 mph knocked down multiple trees and power lines throughout the city of Altoona. One tree was reported down on a residence on 7th Avenue.

7. Jan 10, 2024High Wind, Blair$45,000
   National Weather Service narrative

   A wind gust estimated near 80 mph knocked over a barn and overturned a vehicle inside of the barn along Piney Creek Road near Williamsburg.

8. Mar 4, 2023High Wind, Blair$40,000
   National Weather Service narrative

   Northwesterly winds occasionally gusting to near 60 mph occurred for several hours in Blair County. The ASOS at Altoona Airport recorded a wind gust to 58 mph, as did a mesonet site near Martinsburg. As a result, there were numerous reports of trees and wires down across the county.

9. Apr 29, 2025Thunderstorm Wind$40,000
   National Weather Service narrative

   A line of severe thunderstorms producing wind gusts estimated at 70 mph knocked down multiple power poles near Sinking Valley. Three barn roofs were also blown off in the area.

10. Jul 5, 2026Flash Flood$30,000
    National Weather Service narrative

    Basement collapse due to considerable flash flooding on West 20th Street.

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 22, 2011

All-time low

−25°FJan 19, 1994

Warmest night

81°FAug 23, 1968

Coldest day

−8°FJan 17, 1982

Wettest day

5.55 inSep 8, 2004

Snowiest day

18.1 inMar 13, 1993

Hottest year

1998mean 54.2°F

Coldest year

1978mean 47.1°F

Wettest year

197257.32 in

Driest year

200524.25 in

Snowiest season

99.9 in1993-94

Station Altoona Blair County Airport (USW00014736), 1,465 ft elevation, 13.3 miles from the population centre. Daily records from 1949 to October 26, 2026; 99.8% 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 USW00014736.
• 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.