09/04/2026
HOW DID THE SEPTEMBER 3 STORM COMPARE WITH STRUCTURAL DESIGN WIND SPEEDS?
A 46-mph wind gust was measured at Pittsburgh International Airport. Farther east, near Greensburg, Adamsburg, and Jeannette, a National Weather Service warning identified a radar-indicated maximum gust of approximately 80 mph. That higher figure was an estimate associated with the storm—not a measured surface gust at a weather station.
For context, residential construction in much of Western Pennsylvania has historically used:
• 90-mph basic wind speed under earlier IRC editions
• 115-mph ultimate design wind speed under more recent editions
These values are not directly comparable without considering the code basis. For design purposes, the modern 115-mph ultimate wind speed is approximately equivalent to the earlier 90-mph allowable-stress criterion. The difference largely reflects a change in engineering calculation format—not a sudden 25-mph increase in expected wind resistance.
Pennsylvania’s Uniform Construction Code took effect in 2004. Homes built before then were subject to the codes, ordinances, construction practices, and enforcement within their individual municipalities, if applicable.
A building designed for the applicable code wind speed is not guaranteed to remain completely undamaged during a lower reported gust. Wind pressures also depend on exposure, building height, roof geometry, topography, openings, and localized thunderstorm effects. Deterioration, missing connections, improper alterations, and falling trees may cause damage at substantially lower speeds.
The better question is not simply:
“Was the wind below the code design speed?”
It is:
“Does the structure have a complete and properly maintained load path capable of transferring wind forces from the roof and walls into the foundation?”
Facts, not fear.
Sources: National Weather Service Pittsburgh; Pennsylvania Department of Labor & Industry; International Residential Code.
Illustrative graphic for general educational purposes; it does not represent an evaluation of a specific structure.
PittDES