Measuring Snowfall

Measuring snow is a rough art and can be very subjective.  A lot depends on frequency and location of your measurement.  Ideally you want a cold flat surface that is somewhat protected from the wind, but not so protected that snowfall measurements will be inaccurate.  Below are some helpful hints for measuring snow.

Surface: 

• First choose a convenient spot away from the obstacles such as a house, garage, shed, fence, large bushes, and trees.  Ideally about 10-12 feet from a 6 foot fence.  These objects aid in the piling up (drifting) of the snow near them.  The ideal spot will usually be in the middle of your back or front yard away from trees. Figure 1 shows several backyard examples with the red oval denoting the best place to measure snow.  When measuring take several readings within the red oval, especially with a backyard like b), where drifting will be more of an issue.

a) b)

Figure 1.  Backyard examples.  Red oval denotes best place to measure snow.

• Ideally a snowboard (Figure 2), an outdoor table, or a deck are the best measuring surfaces.  A snowboard is simply a piece of plywood cut in about a 2 ft square and painted white.  If you use a snowboard on the ground, then a flag or some other marker will help you locate it during snowy weather. 

Figure 2. White piece of wood is a snowboard.

• Pavement is OK if it’s cold (below 32 F), but should not be used under milder conditions due to melting.
• Grass is too uneven...especially in the Fall and after Greenup in the spring.  Grass may be used in the middle of winter, if it’s dead and not puffy.
• Bare ground is OK.  Do not mistake an ice layer or crusted snow as the “ground”.
• Picnic table and autos are fine if winds are light.

• If possible, clean off the surface you are measuring for your next measurement (Figure 3).  If measuring on a surface that already has a covering of snow, then subtract the old snow from the new.

Figure 3.  Cleaning snowboard.

Wind/Drifting:

• If drifting is a problem, take several measurements and average them.  Bare ground will give you a zero reading.  Do not include the largest drifts.

Frequency: 

• Do not measure more than once an hour.
  • Hourly measurements will be extremely helpful when snowfall rates are exceptional (1" or more per hour).  In general, once every several hours (3 to 6) is preferable (unless the snow is melting).

Total snowfall: 

• Report to the nearest tenth of an inch (Figure 4).

Snow Depth: 

• Report to the nearest whole inch (Figure 4).  Roundup at 0.5 inches.

Figure 4.  Measuring Snowfall.  If this were your total snowfall then it would measure 1.8 inches.  If this were your total snow depth then you would report 2 inches.

Summary:

    The optimal conditions for measuring snow are to find a piece of wood (wooden picnic table or piece of ply-wood) in an open area where snow will fall unhindered and yet not drift from blustery winds.  After measuring the snow, clean off the piece of wood for your next reading.