islandnet.com

kOee5 TIL that during a particularly cold spell in the town of Snag (Yukon) where the temp reached -83f (-63.9c) you could clearly hear people speaking 4 miles away along with other phenomenon such as peoples breath turning to powder and falling straight to the ground & river ice booming like gunshots.
jQ4v TIL it is not coldest just before the dawn - it is coldest about an hour after dawn. The temperature only begins to increase once the incoming solar radiation overcomes the heat radiating away from earth.
Ob9Y TIL during the Great Smog in London, 1952, visibility was so poor that pedestrians were helped through the streets by the blind.