Honolulu’s building permits size an ordinary house roof for a 138 mph wind gust, and that single number drives the nailing pattern, the sheathing fasteners, and the straps holding the roof to the walls more than the shingle brand ever will. The gust is a three-second burst measured 33 feet up in open, flat terrain, not the sustained wind a hurricane forecast quotes. Check with the county building department before assuming a lower design value applies to a specific site, since local hills and shoreline exposure can push the real figure higher.
What wind speed must a roof withstand in Hawaii?
The design figure for Honolulu is 138 mph, according to the American Society of Civil Engineers’ ASCE 7-16 standard, the edition behind the current permit cycle. It’s a 3-second gust measured at 33 feet above ground in Exposure C, open terrain, for Risk Category II, the classification that covers a typical single-family or two-family home rather than a hospital or fire station held to a higher standard. The newer ASCE 7-22 standard maps the same point at 139 mph, a difference too small to change anything on a truss drawing, and it’s worth knowing only as the coming edition, not as the number a plan reviewer uses today.
This gust measurement isn’t what a hurricane advisory calls wind speed. A forecast reports a sustained value averaged over one or two minutes. The code’s 3-second gust captures the momentary peak that actually rips a shingle tab loose or lifts a panel of sheathing. The two numbers describe different things, and comparing them directly tells a reader nothing useful.
What the number changes on the roof
Honolulu sits inside a hurricane-prone region, a defined term in the code rather than a description of the weather. That status is what triggers roof-to-wall uplift connections, a continuous load path from ridge to foundation, and tighter fastening schedules for both shingles and the sheathing underneath. Roof edges, rakes, and ridges see the highest uplift pressures of any part of the roof, which is exactly where a poorly finished edge fails first once a storm arrives.
Hawaii is also flagged as a special wind region on the ASCE map, meaning the mapped figure is a starting point, not a finished answer. Local topography, a ridge, a saddle, or a channel between hills, can accelerate wind well past the mapped value, and the map by itself does not account for that. The authority having jurisdiction, meaning the county building department, has the final say on whether a specific site needs a higher design value than the map alone suggests.
Does Hawaii require impact-rated roofing or shutters?
At Honolulu, the mapped wind speed of 138 mph under ASCE 7-16 falls below the threshold that triggers a wind-borne debris requirement, so the map alone does not obligate impact-rated glazing or shutters on an ordinary house there. That’s useful news for cost, but it comes with a caveat: it describes the reference city under the mapped value, and a county elsewhere in the state could still adopt a stricter local amendment.
Who actually sets the requirement
The rules themselves come from the Hawaii State Residential Code, based on the 2018 International Residential Code, a statewide minimum that individual counties may exceed but not weaken. The Hawaii State Building Code Council administers it, and counties have up to two years to adopt or amend the state code, after which it becomes their interim code by default. An emergency proclamation on affordable housing has, at times, suspended the Council’s power to amend or update the statewide code, so the current status is worth checking directly with the county building department before assuming what applies.
Where a wind-borne debris region does apply, and parts of Hawaii’s coastline can cross that line even where the reference city does not, the requirement targets openings: windows, doors, and skylights. A broken window during a storm turns a sealed building into a pressurized one, and that internal pressure pushes up on the roof deck from underneath, which is why code writers treat the roof and the windows as one connected problem rather than two separate ones.
What the roof adds on its own terms, independent of the openings question, is a fully sealed roof deck, meaning taped or sealed sheathing seams that keep water out even if shingles tear away, ring-shank nails instead of smooth-shank for pull-out resistance, a secondary water barrier under the primary underlayment, and continuous straps or clips that carry uplift loads down through the wall framing to the foundation. Those elements matter at Honolulu’s 138 mph design value whether or not the debris-impact rule ever applies, because uplift on the roof itself doesn’t wait for a window to break first.
Does snow ever matter for a roof in Hawaii?
No, not at the elevations where nearly everyone in Hawaii lives. The design ground snow load at Honolulu is 0 psf under the ASCE 7-16 snow map, which assigns zero below 1,000 feet of elevation across the islands. Wind, not snow, is the load that drives roof framing, sheathing, and fastening decisions here, and it dominates statewide rather than just at the reference city, because Hawaii’s mapped wind figures apply as a special wind region across the whole state.
Snow does occur at high elevation on Mauna Kea and Mauna Loa, but that’s a case entirely outside the residential roofs this page is discussing, and ordinary house design in Hawaii builds in no snow allowance at all.
That doesn’t mean an unusual weather event causes no trouble on a roof that never designed for it. The exposure runs through drainage, not weight. A flat or low-slope roof with blocked scuppers or clogged drains ponds water fast when a storm drops rain faster than the roof can shed it, and standing water finds every weak seam eventually. Ponding, not snow load, is the real risk on a Hawaiian low-slope roof during an unusual storm, and keeping drains and scuppers clear matters here more than any snow load table ever would.
How much does heat shorten a roof in Hawaii?
Honolulu averages 18.7 days a year at 90°F or hotter, according to NOAA’s National Centers for Environmental Information 1991-2020 climate normals for the Honolulu reference station, and the entire state falls into IECC climate zone 1A, the hottest and most humid zone the 2021 International Energy Conservation Code defines, with no county exceptions. That single statewide zone is unusually convenient. Most states span several zones, forcing a reader to look up their own county, while Hawaii uses the same insulation table row everywhere.
Heat and ultraviolet light are what actually wear out an asphalt shingle, not weight or impact. Asphalt shingles contain volatile oils that keep the mat flexible. UV and sustained heat drive those oils out over years, and once they’re gone the mat stiffens and cracks instead of flexing with temperature swings. Granules embedded in that softened asphalt let go once the surface beneath them hardens, and a shingle that has lost its granule coat loses its UV protection even faster, so the process accelerates once it starts.
Why attic ventilation matters here
A dark asphalt shingle roof deck in full Hawaiian sun runs well above the air temperature measured at head height, and a poorly ventilated attic traps that heat underneath the deck instead of letting it escape. That trapped heat cooks the underlayment and the underside of the sheathing from below at the same time the sun bakes the shingles from above, a harsher exposure than either surface would see alone. Attic ventilation is a roof lifespan question in this climate, not only a comfort question for the space underneath it. Ridge vents, soffit vents, and a clear airflow path between them measurably reduce that trapped heat.
Roof color and reflectance work the same equation from the other direction. A lighter or more reflective surface absorbs less solar energy to begin with, lowering both the deck temperature and the attic temperature underneath. The underlayment’s own temperature rating matters too, since not every product is rated for the same sustained deck temperature, and one chosen for a cooler climate can degrade faster under Hawaii’s heat load than one rated for it.
What roofing material suits Hawaii best?
At Honolulu’s 138 mph design wind speed, the fastening schedule and the deck underneath matter more than which material sits on top. A shingle rated for high wind performs only as well as the nailing pattern actually used on the roof, so the choice of covering is secondary to getting that installation detail right, whatever category ends up on the house.
Comparing the categories under wind and heat
| Material | Wind performance | Behavior under heat |
|---|---|---|
| Architectural asphalt shingles | Carry a manufacturer wind rating tied to a specific nailing pattern, six-nail patterns and starter strip adhesion matter most at rakes and ridges | Dark colors run hotter, granule and oil loss accelerates with UV and heat exposure |
| Standing-seam metal | Concealed clips distribute uplift along the panel length rather than at discrete nail points, an advantage at high gust speeds | Reflective finishes lower deck temperature, the material doesn’t dry out or shed granules the way asphalt does |
| Concrete or clay tile | Heavy individual units resist uplift by mass, but the fasteners and clips holding each tile are the actual failure point in high wind | Long-lived under direct sun, the added mass is a structural load the framing must be engineered to carry |
Architectural asphalt shingles remain the most common covering because they’re familiar to installers and simple to service, but their wind performance depends entirely on installation matching the rated nailing pattern. A shingle box printed with a high wind rating and then fastened at a lower standard delivers the lower standard’s performance, not the rating on the box.
Standing-seam metal roofing distributes uplift load through concealed clips along each panel’s length rather than through discrete fastener points, which is one reason it tends to perform well at high gust speeds when installed correctly. A reflective finish also tends to run cooler, which matters given Honolulu’s 18.7 average days a year above 90°F.
Concrete and clay tile hold up well under decades of direct sun and don’t suffer the oil loss that ages asphalt, but the units themselves are heavy, adding a load the roof framing has to be engineered to carry, and in high wind the fasteners and clips holding individual tiles down are the actual weak point, not the tile material itself.
Where heat is the dominant concern, a lighter or more reflective surface lowers deck and attic temperature regardless of which category is chosen, though that’s a comfort and durability factor layered on top of the wind design, never a substitute for it. For how these same wind and heat factors play out under a different design wind speed, see Texas’s roof wind speed and heat rules, and for general guidance on getting a roof project through permitting, see Roofing.