Tulsa County, OK | 110-120 mph Design Wind Speed | Oklahoma IBC | Tornado Alley | Exposure B/C
Calculate Tulsa Wind Loads Now →Tulsa, located in Tulsa County, Oklahoma, has elevated wind load requirements reflecting its position in the heart of Tornado Alley. Oklahoma uses the Oklahoma Uniform Building Code (OUBC), which adopts the International Building Code (IBC) with state-specific amendments. Design wind speeds for Risk Category II structures typically range from 110-120 mph (3-second gust) based on ASCE 7-22 wind speed maps.
These requirements exist because Tulsa experiences some of the nation's most frequent severe weather including violent tornadoes, severe thunderstorm complexes, damaging hail, and extreme straight-line winds. As Oklahoma's second-largest city and the former "Oil Capital of the World," Tulsa has a rich history of Art Deco architecture that must withstand intense Tornado Alley conditions year after year.
Design Wind Speed (Risk Category II): 110-120 mph (3-second gust, varies by location)
Design Wind Speed (Risk Category III): ~125-135 mph
Design Wind Speed (Risk Category IV): ~135-145 mph
Exposure Category: B (urban), C (open areas)
Building Code: Oklahoma Uniform Building Code (adopts IBC)
Wind Load Standard: ASCE 7-22 (current edition)
County: Tulsa County
Weather Risks: Violent tornadoes, severe thunderstorms, hail, Tornado Alley core
Tulsa's design wind speed of 110-120 mph for Risk Category II structures reflects the city's location in the heart of Tornado Alley and exposure to some of the nation's most severe convective weather. These elevated wind speeds—higher than coastal non-hurricane regions—account for:
Recent severe weather events include the devastating May 2011 Joplin EF5 tornado that occurred just 100 miles northeast of Tulsa, killing 161 people. Tulsa County itself has experienced numerous violent tornadoes including the 1993 Catoosa EF4 tornado. The May 2013 Oklahoma tornado outbreak produced multiple EF4+ tornadoes across central Oklahoma. Severe thunderstorm derechos regularly produce widespread wind damage throughout the Tulsa metro area.
Calculating wind loads for Tulsa projects requires following ASCE 7-22 methodology as adopted by the Oklahoma Uniform Building Code. The fundamental velocity pressure equation is:
qz = 0.00256 Kz Kzt Kd Ke V²
For Tulsa with V = 115 mph (typical Tulsa velocity) and standard conditions, the resulting pressures are elevated compared to most non-Tornado-Alley regions. A Tulsa project with:
Results in a velocity pressure of approximately qz = 24.0 psf—significantly higher than coastal non-hurricane regions and reflecting Tulsa's severe weather exposure.
For open suburban areas using Exposure C (southern Tulsa suburbs and developing areas south of Creek Turnpike), the pressures increase substantially due to higher velocity pressure coefficients for open terrain exposure.
Tulsa has adopted the Oklahoma Uniform Building Code (OUBC), which is based on the International Building Code (IBC) with Oklahoma-specific amendments. The City of Tulsa also adds local amendments addressing specific Tulsa conditions.
Key Tulsa building code considerations:
You can access Tulsa building permits and requirements through the City of Tulsa Working in Neighborhoods Department.
Tulsa projects must be classified into Risk Categories per ASCE 7-22 Table 1.5-1. Higher risk categories require increased design wind speeds:
| Risk Category | Tulsa Design Wind Speed | Building Types |
|---|---|---|
| Risk Category I | ~105-110 mph | Agricultural facilities, temporary structures, minor storage |
| Risk Category II | 110-120 mph | Residential, commercial, most standard occupancies |
| Risk Category III | ~125-135 mph | Schools, assembly >300, substantial hazardous materials |
| Risk Category IV | ~135-145 mph | Hospitals, fire stations, emergency shelters, EOCs |
Tulsa projects require careful Exposure Category determination based on surrounding terrain and development density:
Exposure Category B (Urban): Most of central and midtown Tulsa qualifies as Exposure B due to dense urban development with numerous buildings, trees, and obstructions. Exposure B assumes urban and suburban areas with buildings having heights generally less than 30 feet extending more than 800 feet upwind. This applies to downtown Tulsa, Cherry Street, Brookside, and established neighborhoods throughout the metro area.
Exposure Category C (Open/Developing Areas): Southern Tulsa suburbs (south of Creek Turnpike), Broken Arrow development areas, and Owasso suburbs may qualify as Exposure C. This includes open terrain with scattered obstructions having heights generally less than 30 feet. Exposure C produces significantly higher wind pressures than Exposure B and is critical for Tulsa's rapidly developing suburban areas.
Engineering Judgment Required: Oklahoma's open prairie terrain surrounding Tulsa means many suburban projects will require Exposure C designation. Professional engineering judgment is essential for proper exposure determination.
Tulsa's wind load requirements are directly influenced by the city's location in the heart of Tornado Alley:
Tornado Alley Core: Tulsa sits in the heart of Tornado Alley where warm, moist air from the Gulf of Mexico collides with cold, dry air from Canada and hot, dry air from the Southwest. This creates some of the world's most violent tornado activity. Tulsa County averages 2-4 tornadoes annually, with violent EF4-EF5 tornadoes occurring periodically throughout the region.
Violent Tornado History: Tulsa has experienced numerous violent tornadoes including the 1993 Catoosa EF4 tornado that devastated areas just east of Tulsa. The broader Oklahoma region experiences frequent violent tornadoes including the devastating May 2013 El Reno EF5 tornado (widest tornado ever recorded) and Moore EF5 tornadoes. While ASCE 7 wind loads are based on synoptic wind events rather than tornadoes, the elevated base wind speeds (110-120 mph) reflect Oklahoma's extreme severe weather exposure.
Severe Thunderstorm Straight-Line Winds: Tulsa experiences frequent severe thunderstorms producing damaging straight-line winds. Derecho events can produce wind gusts exceeding 90-110 mph across the metro area. Mesoscale convective systems (MCS) regularly produce widespread wind damage throughout eastern Oklahoma.
Extreme Hail Risk: Tulsa is consistently ranked among America's most hail-prone cities. Giant hail (2+ inches diameter) occurs regularly during severe weather season. Roof systems must be designed to resist both wind uplift and hail impact, requiring integrated design approaches specific to Tornado Alley conditions.
Tulsa zip codes span a large geographic area with relatively consistent wind speed requirements. Common Tulsa zip codes include:
The WindLoadCalc.com wind load calculator automatically applies the appropriate Tulsa wind speed based on your specific zip code or street address, accounting for local terrain conditions and exposure.
Wind load calculations for Tulsa building permits have varying PE requirements depending on building type and complexity:
Oklahoma Professional Engineers must be licensed through the Oklahoma State Board of Licensure for Professional Engineers and Land Surveyors.
Engineers, architects, and contractors should reference these official resources for Tulsa wind load compliance:
The wind load calculator at WindLoadCalc.com automatically applies all Tulsa-specific requirements:
WindLoadCalc.com automatically handles all Tulsa-specific requirements including the 110-120 mph design velocity, appropriate Exposure Category selection, Risk Category adjustments, and component pressure coefficients. Simply enter your Tulsa project address or zip code for instant, accurate calculations.
Calculate Tulsa Wind Loads Now →Tulsa and Oklahoma City (OKC) share similar Tornado Alley exposure with comparable wind load requirements:
| Requirement | Tulsa | Oklahoma City |
|---|---|---|
| Design Wind Speed | 110-120 mph | 110-120 mph |
| Exposure Category | B (urban), C (suburban/open) | B (urban), C (suburban/open) |
| Building Code | Oklahoma Uniform Building Code | Oklahoma Uniform Building Code |
| Tornado Alley Position | Heart of Tornado Alley | Heart of Tornado Alley |
| Historical Tornado Damage | Multiple EF4+ tornadoes historically | Multiple EF5 tornadoes (May 2013 Moore) |
| Primary Weather Risk | Violent tornadoes, severe storms, hail | Violent tornadoes, severe storms, hail |
Both Tulsa and Oklahoma City require rigorous wind load design reflecting Oklahoma's position as the most tornado-prone state in America. Engineers working in either city must apply elevated wind speeds and conservative design practices appropriate for Tornado Alley conditions.
Tulsa's history as the "Oil Capital of the World" created a concentration of stunning Art Deco architecture that must be preserved while meeting modern wind load requirements:
Engineers working on Tulsa historic preservation projects should consult with the Tulsa Preservation Commission to ensure wind load retrofits meet both structural and historic preservation standards.
WindLoadCalc.com provides instant, accurate wind load calculations for Tulsa projects. Our software automatically handles the 110-120 mph velocity range, Exposure B/C determination, and generates PE-ready reports for building permit submission in Oklahoma's most challenging severe weather environment.
Try Tulsa Wind Load Calculator →