Share of US land with unusually high summer temperatures

Unusually hot summers are defined based on daily maximum temperatures. At each station, the recorded highs are compared with the full set of historicalrecords. After averaging over a particular month or season of interest, the warmest 10% of years are defined as “unusually hot”.

191020201920194019601980200020%Daily highs
Share of US land with unusually high summer temperatures

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