Free. Read straight from the federal regulation.
Every county in the country sits in a HUD wind zone, and every manufactured home is built for one. Buy a home built for the wrong zone and it cannot be installed. Check the county before you write a check.
Every manufactured home is built for one wind zone, and every county sits in one. If the home's zone is lower than the county's, it cannot legally be installed there, no matter how good the deal looks.
Pick a county and you'll get its wind zone, its roof load zone, and what that rules in or out.
15 psf horizontal · 9 psf uplift
The default for every county the regulation does not name. About 83% of the country's mobile homes sit in a Zone I county.
100 mph design wind speed
144 counties in 11 Gulf and Atlantic states, including every Florida county outside Zone III. The structure has to be designed by a professional engineer or architect.
110 mph design wind speed
121 counties: 14 in Florida, 8 Louisiana coastal parishes, Carteret, Dare and Hyde in North Carolina, all of Hawaii and every US territory. The strictest standard HUD sets.
The zones are minimums, so they only run one way. A home built for Zone III can be installed in a Zone I county. A Zone I home in a Zone II county is the problem, and it shows up in real deals as a cheap home bought two states inland and hauled toward the coast.
Scouting an area before you have a county? The mobile homes by ZIP code lookup shows how many homes are there, which counties the ZIP covers and whether it crosses a wind zone line.
A home's wind zone is set at the factory, written on its data plate, and fixed for life. A Zone I home cannot be upgraded into a Zone II home afterwards.
That makes it one of the few hard yes-or-no answers in a mobile home deal. A bad roof, soft floors or old plumbing can be priced in. A wrong wind zone ends the deal.
It bites hardest on the deals that look best: a singlewide priced well below the local market, sitting a few hundred miles inland, that has to be moved to a coastal park. The price makes sense right up until you read the data plate.
So check the data plate before the inspection. The regulation requires it to be posted inside the home and to state the wind and roof load zones the home was built for. It is the cheapest check you will make all week.
Directly from 24 CFR 3280.305(c), the HUD Manufactured Home Construction and Safety Standards. The regulation itself names every Wind Zone II and Wind Zone III county, and every North and Middle Roof Load Zone county, in its own text. There is no HUD map file or API. The legal text is the map. Anything the regulation does not name falls into Wind Zone I and the South Roof Load Zone by its own wording.
Because the regulation has not kept up. It still says "Dade," which became Miami-Dade in 1997, and "Princess Anne," a county that was absorbed into the City of Virginia Beach in 1963. It also misspells Terrebonne, Vermilion, Lafourche, Chisago and Cheboygan. This tool matches the regulation's names onto the Census Bureau's current county list by hand, so you get the county you would actually find on a map.
Because the regulation does not give one. It places "the coastal regions of Alaska" in Wind Zone III and defines them by the 90 mph isotach on a 1988 map. That is a line on a map, and it names no boroughs. Guessing which boroughs it crosses would be inventing a legal answer, so this tool says so instead. All 30 Alaska boroughs and census areas are in the North Roof Load Zone, which the regulation does state plainly.
Yes. The regulation puts all of Florida in Wind Zone II except the counties it names for Zone III. It is worth knowing that the sentence doing that work contains a broken cross-reference: it points at paragraph (c)(1)(i)(C), which is part of the design-load text and contains no county list at all. The Zone III counties are in paragraph (c)(2)(iii)(B). The intent is unambiguous, but if you go looking for the list where Florida's entry sends you, you will not find it.
Snow. North Roof Load Zone homes are built for 40 psf, Middle Roof Load Zone for 30 psf, and South Roof Load Zone for 20 psf. It runs on the same logic as wind: a home built for a heavier load is fine anywhere, a lighter one is not. Eight Maine counties and all of Alaska make up the entire North zone.
No. This is the federal construction standard, and it is the floor. The regulation also lets HUD set stricter requirements for specific areas through rulemaking, and your state or local authority may have its own rules on installation, anchoring and foundations. Use this to rule a home out fast, then confirm with the authority having jurisdiction before money moves.
24 CFR 3280.305(c), HUD Manufactured Home Construction and Safety Standards - Structural design requirements. County names reconciled against the US Census Bureau 2020 county reference file.
Regulation text checked September 11, 2026. The wind and roof load zones change only by rulemaking published in the Federal Register, so this does not drift between amendments. Still, confirm anything you are about to spend money on.
The inspection checklist has 23 and the title checklist has 18. They come with the book, the deal calculator and the contracts.
