Frostline.info

Frost line depth in Becker, MN 55308

Frost can reach about 52 inches deep in typical soil here (45″ in clay to 66″ in sand). Local codes in climates like this commonly set footing depth at 42 to 66 inches.

Severe frost
Estimated frost depth
52″
typical silt/loam soil
Typical code footing depth
42–66″
rule of thumb for this climate
Design freezing index
2,844
°F-days, 100-year winter
Mean annual temp
42.6°F
nearest stations
52″ 0″12″24″36″48″60″72″84″ 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)66″
Silt / loam (typical yard soil)52″
Clay (holds water)45″

Estimates use the modified Stefan equation with a turf / light-snow surface. Bare, plowed or paved ground freezes deeper; deep snow cover keeps frost shallower. How we calculate this.

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 Sherburne County building or permitting office in Minnesota and call 811 before digging.

What this means for your project in Becker

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 66″ 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 52″ 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; in a climate this cold, 4 feet or more is common for service lines.

Slabs & frost-protected foundations

Frost-protected shallow foundations (IRC R403.3) use the 100-year air freezing index — 2,844 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather data behind this estimate

NOAA weather stationDistance100-yr AFI
Milaca, MN23.5 mi2,881
Collegeville St John U, MN28.9 mi2,846
Maple Plain, MN30.5 mi2,780

55308 ranks #4 of 6 ZIP codes in Sherburne County for frost depth (1 = deepest).

Nearby ZIP codes

All of Sherburne County →

Common questions

How deep is the frost line in Becker, MN?

Based on NOAA's 100-year air freezing index of 2,844 °F-days for 55308, frost can reach about 52 inches in typical soil, 45 inches in clay and 66 inches in sand or gravel.

How deep do deck footings need to be in 55308?

Footings must sit below the local frost line and at least 12 inches below undisturbed soil. In climates like Becker, codes commonly set the depth at 42 to 66 inches. The Sherburne County building department sets the exact requirement.

Why does soil type change the frost depth?

Wet clay holds a lot of water, and freezing that water releases heat that slows the frost. Dry sand and gravel hold little water and conduct cold faster, so frost goes deeper.

Where does this data come from?

Freezing-index values come from NOAA National Climatic Data Center station records (1951–80), the same data behind the air-freezing-index map in the International Residential Code. We average the three nearest stations, weighted by distance.