Lack of below zero temperatures in Chicago - FOX 35 News Orlando

The coldest air mass in almost two years has reached Chicago.

The forecast low Monday night at O'Hare is -2 and -5 in Rockford. The last time Chicago saw of low temperature below zero was back on February 10th, 2011. That's 710 days ago. That is now 4th longest on record without of subzero overnight low. The 3rd longest streak in this category was 718 days ending January 16th, 1954.

The really odd thing about this extremely cold air mass that has invaded Chicago is the lack of snow on the ground. Between 1960 and 2010, there has been 469 days where the mercury dipped below zero. Only 16 of those days occurred with no scow on the ground. Monday night could be lucky 17.

The National Weather Service in Romeoville said that if Chicago had a descent snowpack on the ground, the overnight low could have dropped all of the way to -20. That just goes to show you the impact that snowpack has on surface air temperatures.

Chicago is still in the midst of a snow drought with only 1.3" so far this season compared to the 12.9" of snow that had fallen through January 21st of 2012.

Chicago has not received 1" of snow on a calendar day since February 24th 2012. That's 332 days. The forecast looks promising this Thursday night with some of the models forecasting between 2 & 3" of snow. There will be no issue of the ground being too warm for the snow to stick and accumulate. This has been a big issue so far this season with the ground either being too warm or too wet from recent rains.