Story by Elizabeth Weise, USA TODAY•2h ago

The forecast map for July 24-28 shows above-average temperatures are likely across most of the nation.©Climate Prediction Center

Summers are always hot. But this summer is different in some profound ways.

Record-breaking temperatures arehitting multiple cities. Phoenix recorded an unprecedented nineteen consecutive days over 110 degrees.Death Valley reached 128 on Sunday.Records are falling everywhere.

It’s not your imagination: This is not a typical summer.

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The extreme temperatures being recorded this summer are the result of the combination of natural variations within the climate system and human-caused climate change,with a hefty serving of El Niño thrown in.

Here’s what to know:

How do we know climate change is fueling this heat? Couldn’t it be just a hot summer?

Natural variability still exists…