ARIZONA · PIMA COUNTY / CITY OF TUCSON

Where the Sonoran Desert Floor Meets the Monsoon Wall

Tucson sits in a low-wind desert basin ringed by four mountain ranges — but summer haboobs and microbursts make exposure, not raw speed, the design driver.

90–100MPH 3-SEC GUST · RISK II
PimaCOUNTY / CITY OF TUCSON
ASCE 7-22ADOPTED VIA IBC
Exp COPEN DESERT TERRAIN

CYAN · WIND CLIMATE

Low Base Speed, Violent Downbursts

Unlike coastal hurricane zones, Tucson's mapped speed is modest — the hazard is the short-fuse monsoon outflow that goes calm-to-60+ mph in minutes.

Monsoon Microbursts

Collapsing summer storms drop straight-line outflow that briefly tops 70+ mph over a narrow footprint.

JUN–SEP

Haboob Dust Walls

Thunderstorm outflow lofts a mile-wide dust wall — 40–60 mph winds with near-zero visibility.

SIGNATURE EVENT

Open-Desert Exposure C

Creosote, mesquite and saguaro block almost no wind, so most of the basin reads full Exposure C.

DEFAULT EXP C

At 30 ft, Exposure C (Kz=0.85) raises velocity pressure about 21% over Exposure B (Kz=0.70) at the same speed — which is why a "B" assumption is the most common Tucson under-design.

VIOLET · TERRAIN & TOPOGRAPHY

A Basin Walled by Four Ranges

Valley floor at ~2,400 ft stays flat (Kzt=1.0); the foothills where peaks climb past 9,000 ft are where topography starts to bite.

Catalina Foothills

Northern slopes can push Kzt above 1.0 from downslope acceleration.

SITE-SPECIFIC

Pass & Canyon Funneling

Rillito and Tanque Verde valleys channel and speed up regional flow.

CHANNELING

Valley Floor

Downtown, the U of A and most of midtown sit flat — Kzt=1.0 applies.

FLAT · KZT 1.0

Minor Elevation Factor

At ~2,400 ft the Ke elevation adjustment is real but small.

KE ≈ 1.0

EMERALD · PERMIT CHECKLIST

What a Tucson Submittal Actually Needs

City of Tucson Planning & Development Services reviews sealed structural calcs against ASCE 7-22.

Mapped Wind Speed

The site's 90–100 mph value pulled from ASCE 7-22 maps by address.

Exposure Justification

Documented Exposure C for open desert — with the rare B case argued.

Topographic Kzt

Required where foothill slopes or ridgelines lift pressures above flat ground.

Risk Category

Schools, hospitals and shelters read a longer-MRI map and higher loads.

MWFRS + C&C

Full-building and component/cladding pressures for the envelope.

Arizona PE / SE Seal

Commercial and multi-family calcs sealed by an Arizona-licensed engineer.

CYAN · ARIZONA NETWORK

Compare Across the Grand Canyon State

Tucson's desert-basin profile differs from Phoenix's broader Sonoran sprawl — check neighboring jurisdictions and the statewide picture.

Phoenix, AZ

Maricopa County valley to the northwest.

SISTER CITY

Arizona Statewide

Full state code adoption and wind picture.

STATE GUIDE

Wind Speed by Location

Look up the mapped gust for any address.

MAP LOOKUP

All State Requirements

Browse every state's adopted edition.

DIRECTORY

Official references: Tucson Planning & Development · Pima County Development Services · AZ Board of Technical Registration · NWS Tucson Monsoon Forecasts.

EMERALD · RUN THE NUMBERS

Solve Tucson Loads from a ZIP Code

Address in, ASCE 7-22 out — the right 90–100 mph value, Exposure C, foothill Kzt flags and PE-ready MWFRS + C&C pressures.

Calculate Tucson Wind Loads Free Resources