Pittsburgh summer nights growing warmer

PITTSBURGH — Our summers have been trending warmer over the last several decades, but especially so at night.

Since 1970, our average overnight low from June through August has trended about 3.5 degrees warmer, which can be attributed to higher levels of humidity and flow out of the south. The daytime highs have trended warmer as well (+2.0 degrees), but not as sharply.

This summer has been especially tough with consistently hot days and uncomfortably warm nights. We’ve already had nine days with morning lows at or above 70 degrees, which is highest through this date since 1934! We’ve also racked up nine 90 degree days so far.