Record Temperatures

Spurred by a warming climate, daily record high temperatures occurred twice as often as record lows over the last decade across the continental United States, new research shows. The ratio of record highs to lows is likely to increase dramatically in coming decades if emissions of greenhouse gases continue to climb.


In fact there were 808 record highs across the continental US during the month of June, compared to 157 record lows during the same period. The ratio of highs temperature records to low temperature records in June was greater than 5 to 1, based on data from theNOAA National Climatic Data Center.   


To give you an idea of how dramatic a shift this is, the ratio of record highs to record lows during the 40 year period from 1950 to 1989 was .95 to 1. 

“Climate change is making itself felt in terms of day-to-day weather in the United States,” says Gerald Meehl, the lead author and a senior scientist at the National Center for Atmospheric Research (NCAR). “The ways these records are being broken show how our climate is already shifting.”


One example of how this is making itself felt in local weather can be seen this year in Washington, DC where the record setting temperatures in June smashed all previous records by a huge margin.

These graphs were prepared by Steve Scolnik of Capital Climate.