Frostline.info

Frost line depth in Yavapai County, Arizona

Frost reaches about 12 inches in typical soil across Yavapai County, from 6″ in the mildest ZIP code to 16″ in the coldest. Codes in this climate commonly set footing depth at 12 to 18 inches.

Shallow frost
Estimated frost depth
12″
typical silt/loam soil
Typical code footing depth
12–18″
rule of thumb for this climate
Design freezing index
139
°F-days, 100-year winter
ZIP codes covered
19
#4 of 15 counties in AZ (1 = deepest)
12″ 0″12″24″36″ ground frozen
Est. frost (typical soil) Typical code footing depth Clay–sand range

Frost depth by soil type

Soil typeEst. frost depth
Sand / gravel (drains well)15″
Silt / loam (typical yard soil)12″
Clay (holds water)10″

County average. Methodology.

Verify before you dig. These are climate-based estimates. The legally required frost depth is the figure your building department publishes in its IRC Table R301.2 (climatic and geographic design criteria). Call the Yavapai County building or permitting office in Arizona and call 811 before digging.

Frost depth by ZIP code in Yavapai County

ZIPCityEst. frostCode range
85324Black Canyon City6″12–18″
86301Prescott14″12–18″
86303Prescott13″12–18″
86305Prescott16″12–24″
86314Prescott Valley14″12–18″
86315Prescott Valley12″12–18″
86321Bagdad15″12–18″
86322Camp Verde8″12–18″
86323Chino Valley16″12–24″
86324Clarkdale9″12–18″
86325Cornville8″12–18″
86326Cottonwood9″12–18″
86327Dewey11″12–18″
86332Kirkland15″12–18″
86333Mayer7″12–18″
86334Paulden15″12–18″
86335Rimrock8″12–18″
86336Sedona8″12–18″
86351Sedona8″12–18″

What this means for your project in Yavapai County

Deck footings & piers

Footings must bear below the frost line and at least 12″ below undisturbed ground. For planning in this area, budget for holes around 18″ deep until your permit office confirms the exact figure.

Fence posts

Set posts at least one-third of their above-ground height. Where frost heave is a problem, carry concrete footings below the frost line (about 12″ here in typical soil) and bell or taper the bottom.

Water & irrigation lines

Bury supply lines below the frost depth. Your water utility or plumbing code sets the minimum cover; add a margin below the estimate above for unusually cold winters.

Slabs & frost-protected foundations

Frost-protected shallow foundations (IRC R403.3) use the 100-year air freezing index — 139 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather stations used

NOAA weather stationDistance100-yr AFI
Jerome, AZ12 mi82
Prescott, AZ12 mi194
Chino Valley, AZ13 mi264
Cordes, AZ24 mi45

Nearby counties

Common questions

What is the frost line depth in Yavapai County?

About 12 inches in typical soil, based on NOAA's 100-year air freezing index. Across the county's ZIP codes the estimate runs from 6 to 16 inches.

How deep should footings be in Yavapai County, Arizona?

Codes in climates like this commonly require 12 to 18 inches. The Yavapai County building department publishes the required frost depth in its adopted code (IRC Table R301.2).

Does frost depth vary within Yavapai County?

Yes. Estimates differ by 10 inches between the coldest and mildest ZIP codes, mostly from latitude and elevation. Check your own ZIP below.