In a mark of just how warm 2016 has been in the U.S., record high temperatures are outpacing record lows by more than 5-to-1, according to data from the National Oceanic and Atmospheric Administration.
This trend is one of the hallmarks of climate change, and is expected to become even more lopsided in favor of record heat if greenhouse gas emissions are not curtailed.
In a climate without a background warming trend, record highs and lows would be expected to balance out over time, even if there are months or years where one side dominates. And the longer a temperature dataset has been kept, the less likely it should be to set any type of record (it’s easier to set a record high or low with only 20 years of data than with 120 years).
In the U.S., the trend of record highs outpacing record lows can clearly be seen in daily temperature data, and has become particularly noticeable since the 1980s.
Through July, the number of daily maximum temperatures that have set a record high this year have outpaced record low daily minimum temperatures by a rate of 5.5-to 1