SNOW WEIGHT AND DENSITY - Snow is less dense than water. A cubic foot of snow can weigh anywhere between 1 to 20 pounds per cubic foot, depending on moisture content. The actual water content of snow generally ranges from 5% to 32%.
Snow density is a function of temperature, wind exposure, and time.
Snow density increases over time as the snow experiences more changes in temperature and wind. Warmer temperatures lead to higher (and heavier) moisture content; the water may re-freeze into ice when the temperature drops.
Wind also scrapes or wears away by friction or erosion on snowflakes, making them smaller, where they fit together more tightly, compacting the snow. This results in heavier and more dense snow, simply due to the windy weather.
The weight of snow is such an important piece of information for a number of reasons...
For instance, a typical scoop of snow with a snow shovel is about 1.5 cubic feet, so there’s a good chance you’re out there lifting more than 30 lbs. over and over again while you’re clearing your driveway. It’s good to know the weight of snow. If it's heavier, frequent breaks are important as over exertion is likely and it's been coined "heart attack" snow for that very reason.
Roofs can also collapse, due to the weight of snow exceeding the load-bearing capacity of a roof structure. Most homes can only hold 20lbs/sq.ft.
In the video above, Meteorologist Brittney Merlot breaks down the science behind 3 different snow weights and amounts and tells us when we need to start paying attention the weight risks.
If you’re considering trying to remove snow from your roof yourself, please see these snow rakes (on Amazon). They are designed to allow snow to be removed while you are standing on the ground. Using a ladder in the snow can be extremely dangerous.
| Weight of Snow |
|---|
| Type of Snow | Lbs per Inch of Depth per Square Foot
(Average) | Lbs per Cubic Foot
(lb/ft3)
(Average)
| Lbs per Cubic Foot
(lb/ft3)
(Range) | Grams per Cubic Centimeter
(g/cm3)
(Range) | Kg per Cubic Meter
(kg/m3)
(Average) | Kg per Centimeter of Depth per Square Meter
(Average) |
Air
(Average weight of air at sea level at freezing.) | 0.007 lbs | 0.08
lb/ft3 | 0.08
lb/ft3 | 0.0013
g/cm3 | 1.29
kg/m3 | 0.0129 kg |
Wild Snow
(Light, very dry new snow. Snow immediately after falling, in extremely cold temperatures, with no wind.) | 0.1 lbs | 1.25
lb/ft3 | 0.62 – 1.87
lb/ft3 | 0.01 – 0.03
g/cm3 | 20
kg/m3 | 0.20 kg |
Ordinary New Snow
(Snow immediately after falling, in below-freezing temperatures, with no wind; fresh, uncompacted snow that has a high volume of trapped air.) | 0.3 lbs | 3.59
lb/ft3 | 3.12 – 4.06
lb/ft3 | 0.05 – 0.065
g/cm3 | 57.5
kg/m3 | 0.58 kg |
New Snow Slightly Compacted by Wind
(Snow immediately after falling, in below-freezing temperatures, with some wind exposure. Less trapped air.) | 0.37 lbs | 4.46
lb/ft3 | 3.93 – 4.99
lb/ft3 | 0.063 – 0.08
g/cm3 | 71.5
kg/m3 | 0.715 kg |
Settling Snow
(Snow less than a day old that is starting to experience some wind and temperature variation.) | 0.68 lbs | 8.12
lb/ft3 | 4.37 – 11.86
lb/ft3 | 0.07 – 0.19
g/cm3 | 130
kg/m3 | 1.30 kg |
Damp New Snow
(Snow immediately after falling, in slightly above-freezing temperatures, with little wind exposure.) | 0.78 lbs | 9.37
lb/ft3 | 6.24 – 12.49
lb/ft3 | 0.1 – 0.2
g/cm3 | 150
kg/m3 | 1.50 kg |
Sugar Snow
(Snow with large grains formed when water vapor freezes onto existing snow crystals.) | 1.04 lbs | 12.49
lb/ft3 | 6.24 – 18.73
lb/ft3 | 0.1 – 0.3
g/cm3 | 200
kg/m3 | 2 kg |
Settled Snow
(Typical after more than one day in place. Snow that has experienced some temperature and wind variation.) | 1.3 lbs | 15.61
lb/ft3 | 12.49 – 18.73
lb/ft3 | 0.2 – 0.3
g/cm3 | 250
kg/m3 | 2.5 kg |
Average Wind-Toughened Snow
(Compacted snow after wind exposure in below-freezing temperatures.) | 1.46 lbs | 17.48
lb/ft3 | 17.48
lb/ft3 | 0.28
g/cm3 | 280
kg/m3 | 2.8 kg |
Wet Snow
(Dense, sticky snow in relatively warm temperatures with little wind. Good snow for making snowballs.) | 1.75 lbs | 21
lb/ft3 | 17 – 25
lb/ft3 | 0.27 – 0.40
g/cm3 | 335
kg/m3 | 3.35 kg |
Wind-Packed Snow
(Hard Wind Slab. Compacted snow after prolonged and heavy wind exposure.) | 1.98 lbs | 23.73
lb/ft3 | 21.85 – 25.6
lb/ft3 | 0.35 – 0.41
g/cm3 | 380
kg/m3 | 3.8 kg |
New Firn Snow
(Firn is granular, icy, highly-compacted, pre-glacial snow. Some ice present.) | 2.47 lbs | 29.66
lb/ft3 | 24.97 – 34.34
lb/ft3 | 0.40 – 0.55
g/cm3 | 475
kg/m3 | 4.75 kg |
| Advanced Firn Snow | 3.12 lbs | 37.46
lb/ft3 | 34.34 – 40.58
lb/ft3 | 0.55 – 0.65
g/cm3 | 600
kg/m3 | 6 kg |
| Thawing Firn Snow | 3.38 lbs | 40.58
lb/ft3 | 37.46 – 43.70
lb/ft3 | 0.6 – 0.7
g/cm3 | 650
kg/m3 | 6.5 kg |
Slush
(Advanced melting snow; snow/water mix.) | 3.75 lbs | 45
lb/ft3 | 35 – 55
lb/ft3 | 0.56 – 0.88
g/cm3 | 720
kg/m3 | 7.2 kg |
Ice with Air Bubbles
(Cloudy ice.) | 4.5 lbs | 54
lb/ft3 | 51.19 – 56.81
lb/ft3 | 0.82 – 0.91
g/cm3 | 873
kg/m3 | 8.73 kg |
Pure Ice
(Ice with no entrapped air.) | 4.77 lbs | 57.25
lb/ft3 | 57.25
lb/ft3 | 0.92
g/cm3 | 917
kg/m3 | 9.17 kg |
Water
(At sea level just above freezing.) | 5.2 lbs | 62.43
lb/ft3 | 62.43
lb/ft3 | 1
g/cm3 | 1000
kg/m3 | 10 kg |
