There was a record low of 4° F early this morning in Central Park, NYC. That is cold and I am happy to be in Florida's warmer temperature of 41° today. I'm even happier to not be in our usually rather frigid apartment.
Despite the record low for the day, this isn't a record low in general. Central Park saw its coldest temperature, an extreme temperature for our zone, on February 9, 1934. That low bottomed out at -15° F. In fact, cold as it is, today's temperature is perfectly within out winter norms.
What is unusual are the high amplitude weather shifts (eg. 55° yesterday, 5° today). Studies have shown that extreme weather changes may very well result from global climate warming. Few want to hear about "warming" causing cold days and nights, but one day may we all understand the difference between weather-influencing, climate dynamics and the daily weather.
Tomorrow we return to Minnesota where the temperatures have been below zero for weeks. None of these temperatures are a big deal for the comfortably heated, and I can attest from experience that -15° will hurt your exposed fingers in less than 5 minutes. There are a lot of suffering people in all the northern tier, people without access to heat, and those on the street who may not know the cold is coming. It is always coldest when we're sleeping. Let's wake up.