Frost Line Depth in Oklahoma City, Oklahoma
- Oklahoma City’s adopted code
- Checked Oct 2026
- Sources
Verified
18in
46 cm · 1 ft 6 in
Set in the building code Oklahoma City has adopted.
Source and how we checked
Document: okc.gov
Climate: 72 nights a year at or below 32 °F (NOAA 1991–2020, Oklahoma City Will Rogers Airport, 7.3 mi).
Checked Oct 2026. Report a correction
How deep is the frost line in Oklahoma City?
Oklahoma City's building authority sets the frost line depth at 18 in (46 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 Oklahoma City?
Oklahoma leaves the frost line depth to each city or county, and Oklahoma City fills it in when it adopts the residential code. The value above comes from Oklahoma City’s own document on okc.gov. See how Oklahoma sets frost line depth.
How deep do footings, decks and water lines need to be in Oklahoma City?
House or garage footing in Oklahoma City: dig at least 18 in (46 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| Project | Depth | Rule |
|---|---|---|
| House or garage footing | 18 in | Below the frost line and at least 12 in deep (IRC R403.1.4) |
| Deck footing (attached) | 18 in | Below the frost line and at least 12 in deep (IRC R507.3) |
| Water service line | 24 in | 6 in below the frost line and at least 12 in deep (IRC P2603.5) |
| Fence post bottom | 18 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 Oklahoma City?
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Average lows are at or below freezing from Dec to Feb. 72 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 27 °F.
NOAA 1991–2020 climate normals, Oklahoma City Will Rogers Airport station, 7.3 mi away, elevation 1,285 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 27 | 30.8 | 39.5 | 47.5 | 57.6 | 66.2 | 70.3 | 69.1 | 61.5 | 49.4 | 37.7 | 29.5 |
| High | 49.3 | 53.8 | 62.9 | 71.1 | 78.9 | 87.5 | 93.1 | 92.2 | 83.9 | 72.8 | 60.7 | 50.4 |
Oklahoma City has fewer freezing nights than 11 of the 23 other Oklahoma places we track. The Oklahoma median is 72. Coldest: Washington County; mildest: Pittsburg County.
How likely is the soil in Oklahoma City to heave?
USDA rates the sampled soil around Oklahoma City as 100% none for frost action (main soils: Norge, Harrah, Teller).
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 Oklahoma City?
Oklahoma City at a glance
- Frost line depth
- 18 in
- County
- Oklahoma County
- Population (2023 est.)
- 702,767
- Mean annual temperature
- 60.1 °F
- ZIP codes (60)
- 73008 · 73012 · 73013 · 73020 · 73026 · 73034 · 73036 · 73049 · 73054 · 73064 · 73071 · 73078 · 73084 · 73097 · 73099 · 73102 · 73103 · 73104 · 73105 · 73106 · 73107 · 73108 · 73109 · 73110 · 73111 · 73112 · 73114 · 73115 · 73116 · 73117 · 73118 · 73119 · 73120 · 73121 · 73122 · 73127 · 73128 · 73129 · 73130 · 73131 · 73132 · 73134 · 73135 · 73139 · 73141 · 73142 · 73145 · 73149 · 73150 · 73151 · 73159 · 73160 · 73162 · 73165 · 73169 · 73170 · 73173 · 73179 · 74851 · 74857