Fresno County, CA | 85-95 mph Design Wind Speed | CBC Title 24 | Agricultural Capital | Exposure B/C
Calculate Fresno Wind Loads Now →Fresno, located in Fresno County, California, has low wind load requirements that are typically less critical than seismic design considerations. As the agricultural capital of America and the heart of the San Joaquin Valley, Fresno experiences moderate wind conditions. California uses the California Building Code (CBC, Title 24), which is based on the International Building Code (IBC) with California-specific amendments. Design wind speeds for Risk Category II structures typically range from 85-95 mph (3-second gust) depending on precise location, with Exposure Category B being typical for urban areas and Exposure Category C for surrounding agricultural regions.
These requirements reflect Fresno's inland Central Valley location with minimal severe wind exposure. Unlike coastal California cities that face higher wind loads, or hurricane-prone regions that require extreme wind resistance, Fresno's wind loads are relatively modest. For most structures in Fresno, seismic design governs the structural system, with wind loads being a secondary consideration that rarely controls the design.
Design Wind Speed (Risk Category II): 85-95 mph (3-second gust, typical range)
Design Wind Speed (Risk Category III): ~100-110 mph
Design Wind Speed (Risk Category IV): ~110-120 mph
Exposure Category: B (urban areas), C (agricultural/open areas)
Building Code: California Building Code (CBC, Title 24)
Wind Load Standard: ASCE 7-22 (current edition)
County: Fresno County
Special Consideration: Seismic design typically governs over wind loads
Fresno's design wind speed of 85-95 mph for Risk Category II structures reflects the city's protected Central Valley location with low wind exposure. The San Joaquin Valley is surrounded by mountain ranges that provide significant wind shielding from coastal storms and severe weather systems. Fresno is not subject to hurricanes, tornadoes are extremely rare, and severe windstorms are infrequent. The moderate wind speeds in ASCE 7-22 acknowledge this low wind risk while still providing adequate protection for occasional wind events.
The primary wind events affecting Fresno are occasional winter storm systems that can produce gusty winds, summer thunderstorm outflows, and rare downslope wind events from the Sierra Nevada. However, these events rarely approach design wind speeds. The flat terrain and agricultural landscape of the San Joaquin Valley typically results in relatively uniform wind patterns without the extreme localized gusts found in coastal or mountainous regions.
Fresno is known as the agricultural capital of America, producing more agricultural value than any other county in the United States. This creates unique wind load considerations for the region's extensive agricultural and food processing infrastructure:
Agricultural Buildings: Barns, equipment storage facilities, packing houses, and processing plants are common throughout Fresno County. These structures often feature large clear-span designs with significant roof areas requiring careful wind pressure analysis.
Food Processing Facilities: Cold storage warehouses, packing plants, and processing facilities require special attention to building envelope performance. Wind-driven air infiltration can impact refrigeration loads and food safety compliance.
Greenhouses and Shade Structures: Lightweight agricultural structures used for crop protection have high wind vulnerability. Component and cladding (C&C) pressures and uplift forces are critical design considerations.
Grain Elevators and Silos: Tall cylindrical structures require specialized wind load analysis including along-wind, across-wind, and torsional effects per ASCE 7-22 Chapter 29.
Solar Arrays: Agricultural land increasingly hosts ground-mounted solar installations. Wind loads on solar panel arrays, particularly uplift and overturning, require detailed analysis.
Fresno's exposure category varies significantly between urban and agricultural areas, which directly impacts wind load magnitudes:
Exposure Category B (Urban Fresno): Downtown Fresno and established residential neighborhoods feature dense development with numerous buildings, trees, and other obstructions. Exposure B assumes urban and suburban areas with buildings having heights generally less than 30 feet extending more than 800 feet upwind.
Exposure Category C (Agricultural Areas): The extensive agricultural regions surrounding Fresno feature open farmland, orchards, and vineyards with scattered trees and farm buildings. This open terrain qualifies as Exposure C, resulting in higher wind pressures than urban Exposure B locations.
Transitional Areas: Areas at the urban-agricultural interface require careful evaluation to determine appropriate exposure category. Conservative design may consider Exposure C for structures near the urban edge.
The difference between Exposure B and C can result in velocity pressure increases of 30-50% for the same wind speed, making proper exposure determination critical for accurate wind load calculations in Fresno County.
Fresno is located in a moderate-to-high seismic zone due to proximity to the San Andreas Fault system and other active California faults. For virtually all structures in Fresno, seismic design will govern the structural system, including:
However, engineers must still verify wind loads for specific components such as roof cladding, windows, wall panels, and equipment anchorage, as wind loads may occasionally control for lightweight building envelope components, particularly in agricultural structures with large surface areas.
Calculating wind loads for Fresno projects requires following ASCE 7-22 methodology as adopted by the CBC. The fundamental velocity pressure equation is:
qz = 0.00256 Kz Kzt Kd Ke V²
For Fresno with V = 90 mph (typical value) and standard conditions, the resulting pressures are low. A Fresno project with:
Results in a velocity pressure of approximately qz = 12.4 psf—substantially lower than hurricane-prone regions and even lower than many inland U.S. cities that experience severe thunderstorms or tornado risk.
For agricultural areas using Exposure C:
Results in a velocity pressure of approximately qz = 15.0 psf—demonstrating the significant impact of exposure category on wind loads.
These modest pressures mean that for the main wind force resisting system (MWFRS), wind loads are rarely critical for typical buildings. However, component and cladding (C&C) pressures for localized elements must still be evaluated as these pressures can be significantly higher than MWFRS pressures.
California has a statewide building code known as the California Building Code (CBC), published as Title 24 of the California Code of Regulations. The CBC is based on the International Building Code (IBC) with California-specific amendments that address the state's unique seismic, fire, and accessibility requirements.
Key Fresno building code considerations:
You can access Fresno building permits and requirements through the City of Fresno Development and Resource Management Department.
Fresno 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 | Fresno Design Wind Speed | Building Types |
|---|---|---|
| Risk Category I | ~80-85 mph | Agricultural facilities, temporary structures, minor storage |
| Risk Category II | 85-95 mph | Residential, commercial, most standard occupancies |
| Risk Category III | ~100-110 mph | Schools, assembly >300, substantial hazardous materials |
| Risk Category IV | ~110-120 mph | Hospitals, fire stations, emergency shelters, EOCs |
California has strict Professional Engineer licensing requirements that apply to wind load calculations and structural design:
Fresno experiences extreme summer heat with temperatures frequently exceeding 100°F. This creates unique building envelope considerations that interact with wind load design:
Engineers, architects, and contractors should reference these official resources for Fresno wind load compliance:
The wind load calculator at WindLoadCalc.com automatically applies all Fresno-specific requirements:
WindLoadCalc.com automatically handles all Fresno-specific requirements including the 85-95 mph design velocity, Exposure Category B/C assignment, Risk Category adjustments, and component pressure coefficients. Simply enter your Fresno project address or zip code for instant, accurate calculations.
Calculate Fresno Wind Loads Now →Fresno's wind load requirements differ from other major California cities:
| Requirement | Fresno (Central Valley) | California Coast | Bay Area |
|---|---|---|---|
| Design Wind Speed | 85-95 mph | 110-130 mph | 95-110 mph |
| Exposure Category | B (urban), C (agricultural) | C or D (open/coastal) | Primarily B (urban/suburban) |
| Wind Risk Level | Low | Moderate | Low |
| Governing Load | Seismic typically governs | Seismic typically governs | Seismic typically governs |
| Typical Construction | Agricultural, residential, commercial | Residential, resort, commercial | Tech campus, commercial, residential |
| Building Code | CBC Title 24 | CBC Title 24 | CBC Title 24 |
While Fresno has the lowest wind loads among major California population centers, engineers must still verify that building components are adequately designed for wind pressures, particularly in agricultural applications and for structures in Exposure C areas.
Fresno zip codes cover a large geographic area within Fresno County. Common Fresno zip codes include:
The WindLoadCalc.com wind load calculator automatically applies the appropriate Fresno wind speed based on your specific zip code or street address.
The San Joaquin Valley's unique geography creates distinctive wind patterns that engineers should understand:
Valley Floor Location: Fresno sits at approximately 300 feet elevation on the San Joaquin Valley floor, surrounded by the Sierra Nevada to the east and Coast Ranges to the west. This valley position provides significant wind protection.
Seasonal Wind Patterns: Winter storms can produce gusty winds, while summer features consistent northwesterly afternoon winds. These patterns are relatively predictable and rarely extreme.
Downslope Winds: Occasional downslope wind events from the Sierra Nevada can produce localized higher winds, though these are infrequent in Fresno compared to foothill communities.
Agricultural Microclimate: Extensive orchards and vineyards create significant surface roughness, further reducing wind speeds compared to barren terrain.
Dust Storms: While not a structural concern, agricultural areas can experience dust storms (haboobs) during summer thunderstorm season, which can impact visibility and air quality but rarely produce damaging winds.
WindLoadCalc.com provides instant, accurate wind load calculations for Fresno projects. Our software automatically handles the 85-95 mph velocity range, Exposure B/C determination, and generates PE-ready reports for building permit submission.
Try Fresno Wind Load Calculator →