Wind Chill Chart

It has been several years now since the National Weather Service, in concert with the greater science community, implemented an upgraded version of the Wind Chill Index.

Researchers concluded that the additional chill on exposed skin was not as harsh, due in some part to the fact that the wind observation is taken at about 30 feet above ground and most of us have our body parts within the first 6 and a half feet of the ground.

Friction from the earth reduces the wind so the speed of the wind at face level is accordingly reduced from the wind reported at 30 feet.

Regardless, under the new formula, a wind chill of 20 below zero or greater is considered dangerous.

Wind Chill Index

More lake effect snow kicks in tonight on the downwind side of the Great Lakes, but generally dry for the remainder of the region.

CE

  • Chris B. Critter

    When the updated wind chill formula (and corresponding chart) came out a few years ago, there was also talk about taking into account solar radiation. What’s the latest on that effort?

    Also, when one discusses wind chill based on the old scale, one should remember to convert to the new value. This not in response to anything specific anyone has said recently. But when one talks about older calculations of wind chill to -40F, -60F, or -80F, keep in mind that those values are much more difficult to occur with the new formula.

  • Craig Edwards

    Days of old, when wind chills were frequently as brutal as 40 below zero will be rare. See the disclamier at the end of the discussion of the new wind chill index. It states that the wind chaill inex could be increased some 10 to 15 degrees by the warmth of the sun.

    Twenty below is the new forty below, for the most part.

    Craig