Meteorologist Tim Buckley of WFMY-TV writes on Facebook:
All 50 states have low temperatures BELOW freezing tonight. (Monday night)
Yes, even Hawaii. Tall mountain peaks there regularly get below freezing, and even get snow.
This typically happens a few times during winter, but is very rare this early in the season.
The low temperature forecast for tonight shows the cold continuing nationally, with perhaps a second night of below freezing temperatures in all 50 states: