MINNESOTA · HENNEPIN COUNTY

Where the Mississippi Meets the Cold-Climate Wind Code

Minneapolis anchors the Twin Cities on the upper Mississippi, where continental-climate extremes, summer derechos, and tornado season shape every wind load review under the Minnesota State Building Code.

105–115MPH 3-SEC GUST · RISK II
B / CEXPOSURE · URBAN VS OPEN
MSBCMINNESOTA STATE CODE
7-22ASCE EDITION REFERENCED

UPPER MISSISSIPPI · WIND CLIMATE

Reading the Twin Cities Wind Map

A continental interior site: moderate basic wind speeds, but real hazard from straight-line storm winds, tornado season, and wind acting on snow- and ice-loaded roofs.

Basic Wind Speed

Risk Category II design speeds run 105–115 mph, with the lower end inside the dense urban core and the upper end on exposed metro edges.

105–115 MPH

Exposure B vs C

Downtown, Uptown and Northeast neighborhoods read Exposure B; lake frontage, the river corridor, and prairie-edge sites push toward Exposure C.

B / C SITE-SPECIFIC

Storm-Season Winds

Summer thunderstorm and derecho gusts regularly reach 70–90 mph and occasionally top 100 mph, the scenarios component-and-cladding design must respect.

DERECHO RISK

Cold + Snow Coupling

Arctic outbreaks below -30°F and a 40–50 psf ground-snow regime mean wind rarely acts alone — combined load cases drive the controlling demand.

COMBINED CASES

Velocity pressure follows ASCE 7-22 as adopted by the MSBC: qz = 0.00256 Kz Kzt Kd Ke. On flat Twin Cities terrain (Kzt = 1.0) at low roof heights, Exposure B uses Kz = 0.70 with Kd = 0.85 for buildings — moving the same site to Exposure C raises Kz to 0.85 at low height, a roughly 21% jump in pressure before any storm refinement.

PERMIT PATH · HENNEPIN COUNTY

What a Minneapolis Submittal Has to Settle

Six checkpoints that decide whether a wind load package clears CPED or Hennepin County review the first time.

Risk Category

Classify per ASCE 7-22 Table 1.5-1; higher categories pull V from a longer-return-period map, not a fixed multiplier.

7-22 TBL 1.5-1

Exposure Call

Run a 360° terrain sweep within 800–1500 ft; lake fetch and prairie edge can flip a site from B to C.

§ 26.7

Snow + Wind Cases

Evaluate wind on snow-loaded roofs, drift at parapets and steps, and rain-on-snow per the combined-load rules.

40–50 PSF GROUND

C&C Pressures

Detail glazing, doors, roof panels and cladding for debris from straight-line and tornadic winds.

COMPONENT & CLADDING

Cold-Toughness

Account for reduced ductility and brittle-fracture risk in welded connections through deep-winter lows.

CHARPY V-NOTCH

PE Seal

Commercial, assembly and public projects need calculations sealed by a Minnesota-licensed Professional Engineer.

MN PE
Risk CategoryMinneapolis Design SpeedRepresentative Buildings
I~100–105 mphAgricultural, temporary, minor storage
II105–115 mphHomes, retail, most standard occupancies
III~120–130 mphSchools, assembly >300, substantial hazard
IV~130–140 mphHospitals, fire stations, shelters, EOCs

REGIONAL CONTEXT · MINNESOTA & BEYOND

How Minneapolis Sits Among Upper Midwest Peers

Comparable continental-interior speeds, with each city tuned to its own terrain and state code.

CityDesign Wind SpeedExposureBuilding Code
Minneapolis, MN105–115 mphB (urban), C (open)Minnesota State Building Code
St. Paul, MN105–115 mphB (urban), C (open)Minnesota State Building Code
Milwaukee, WI105–110 mphB (urban), C (lakefront)Wisconsin Commercial Building Code
Des Moines, IA110–120 mphB typicalIowa State Building Code (IBC)
Fargo, ND110–120 mphB/C typicalNorth Dakota State Building Code

RUN THE NUMBERS

Calculate Minneapolis Wind Loads in Minutes

Enter a Twin Cities address or zip code and get ASCE 7-22 velocity pressures, Exposure B/C handling, Risk Category speeds, and PE-ready MWFRS and C&C output for CPED or Hennepin County submittal.