Lowest Windchill in U.S. History

Mount Washington, New Hampshire is well known to most meteorologists. 

A mountain-top weather station there is famous for possessing the highest near-surface wind speed ever recorded in the U.S.:  231 mph.

But today, the Mount Washington Observatory has broken another record:  the lowest windchill temperature ever recorded in the U.S.

Reminder:  windchill temperature combines wind and temperature to provide a measure of how much heat you are losing when you are outside.  Lower windchill temperature means a faster loss of heat from your skin.

If there is no wind, temperature and windchill temperature are the same.  But as wind speed increases, the windchill temperature drops below the effective temperature, since wind increases the loss of heat from your skin.    

The previous U.S. windchill record was -100F observed at McGrath Alaska.  That record has now been replaced by -107F at Mount Washington today, the combination of a temperature of -46F and windspeed of 95 mph (see below)

Potentially, the windchill may decline even further during the next few hours.

Windchills below -98F are not even shown on the official National Weather Service windchill chart (below).  At a windchill below -100F, frostbite occurs on exposed skin with 1-3 minutes.

Taking a broader view, the current temperatures over the Northeast US are stunning, with teens over coastal Long Island to around -20F over NE New York.

Several daily records should be broken for record cold during the next day.

Coupled with powerful winds, the windchills across the Northeast range from -50F over Maine and -11F over coastal New England, to -20/-30F over upstate NY.  

The Northwest had a blustery day today, and some showers and typical temperatures are expected this weekend.  Yawn.

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