Frost Line Depth in Prince George's County, Maryland
- Prince George's County’s adopted code
- Checked Oct 2026
- Sources
Verified
30in
76 cm · 2 ft 6 in
Set in the building code Prince George's County has adopted.
Source and how we checked
Document: labor.maryland.gov
Climate: 103 nights a year at or below 32 °F (NOAA 1991–2020, Upper Marlboro 3 Nnw, 4.6 mi).
Checked Oct 2026. Report a correction
How deep is the frost line in Prince George's County?
Prince George's County's building authority sets the frost line depth at 30 in (76 cm). Footings, piers and other permanent supports must reach at least this depth (IRC R403.1.4.1).
Who sets the frost line depth in Prince George's County?
Maryland leaves the frost line depth to each city or county, and Prince George's County fills it in when it adopts the residential code. The value above comes from Prince George's County’s own document on labor.maryland.gov. See how Maryland sets frost line depth.
How deep do footings, decks and water lines need to be in Prince George's County?
House or garage footing in Prince George's County: dig at least 30 in (76 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| Project | Depth | Rule |
|---|---|---|
| House or garage footing | 30 in | Below the frost line and at least 12 in deep (IRC R403.1.4) |
| Deck footing (attached) | 30 in | Below the frost line and at least 12 in deep (IRC R507.3) |
| Water service line | 36 in | 6 in below the frost line and at least 12 in deep (IRC P2603.5) |
| Fence post bottom | 30 in | No code rule; common practice is below the frost line |
Work out posts, concrete and footing sizes with the fence post depth calculator or the deck footing calculator.
How cold does it get in Prince George's County?
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Average lows are at or below freezing from Dec to Feb. 103 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 24.7 °F.
NOAA 1991–2020 climate normals, Upper Marlboro 3 Nnw station, 4.6 mi away, elevation 130 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 24.7 | 25.9 | 32.8 | 43.5 | 53.5 | 62.7 | 67.3 | 65.3 | 58.2 | 45.6 | 35.5 | 28.8 |
| High | 43.9 | 46.8 | 54.7 | 66.5 | 74.8 | 83.5 | 88 | 86.3 | 79.9 | 68.8 | 58 | 48 |
Prince George's County has more freezing nights than 4 of the 6 other Maryland places we track. The Maryland median is 98. Coldest: Bowie; mildest: Gaithersburg.
What frost line depth do towns near Prince George's County use?
4 official codes near Prince George's County are verified; each links to its document.
| Place | Verified frost line | Distance |
|---|---|---|
| Calvert County | 24 in | 27 mi away |
| Howard County | 30 in | 30 mi away |
| Baltimore | 30 in | 35 mi away |
| Frederick County | 30 in | 53 mi away |
How likely is the soil in Prince George's County to heave?
USDA rates the sampled soil around Prince George's County as 2% none, 1% low, 83% moderate, 14% high for frost action (main soils: Udorthents, Marr, Dodon).
USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.
How do you confirm the frost line before you dig in Prince George's County?
Prince George's County at a glance
- Frost line depth
- 30 in
- Population (2023 est.)
- 947,430
- Mean annual temperature
- 56 °F
- ZIP codes (40)
- 20601 · 20607 · 20608 · 20613 · 20623 · 20705 · 20706 · 20707 · 20708 · 20710 · 20712 · 20715 · 20716 · 20720 · 20721 · 20722 · 20735 · 20737 · 20740 · 20742 · 20743 · 20744 · 20745 · 20746 · 20747 · 20748 · 20762 · 20769 · 20770 · 20771 · 20772 · 20774 · 20781 · 20782 · 20783 · 20784 · 20785 · 20903 · 20904 · 20912