Frost depth by state
The frost depth is the depth the ground freezes to. Your footing goes below it. This is the published figure for each state, and the hole depth it produces.
Pick your state
| State | Frost depth | Hole depth |
|---|---|---|
| Minnesota | 42–60″ | 48–66″ |
| Wisconsin | 42–48″ | 48–54″ |
| Michigan | 42–60″ | 48–66″ |
| North Dakota | 60″ | 66″ |
| Maine | 48–60″ | 54–66″ |
| New York | 48″ | 54″ |
| Pennsylvania | 42″ | 48″ |
| Ohio | 32″ | 38″ |
| Illinois | 36″ | 42″ |
| Colorado | 42–60″ | 48–66″ |
More states
The states above are the ones where a dedicated page is worth reading. For the rest, the general frost depth page covers the regional bands — Gulf Coast, Mid-South, Mid-Atlantic and lower Midwest, Upper Midwest and New England — and what each one means for a footing.
What this page does not tell you
- It does not replace your local building department. These are the common published state values. Your county may enforce a different one.
- It does not cover soil. Depth is about temperature. Expansive clay, fill, or rock at the bottom of the hole is a separate problem.
- It does not cover load. Diameter and concrete volume come from the load, not the climate.
Related
Questions people actually ask
What is frost depth?
The depth the ground freezes to. A footing has to sit below that line, which is why footings go deeper than the frost depth — the extra is working room above the frozen zone.
How deep should a deck footing be?
Below the local frost depth. That figure runs from nothing in the Deep South to 60 inches or more in the northern states, and it is set by the state code, then enforced by your county.
Do I need a permit for a deck?
Almost always, for an elevated deck. Most jurisdictions require one for anything more than 30 inches off the ground or over 200 square feet, and it is checked before the hole is dug.
Is the state frost depth the number my county uses?
Usually, but not always. Some counties enforce a deeper figure than the state publishes, and a few local jurisdictions publish their own. The number on your permit is the one that matters.