NASA: May 2017 the 2nd warmest May in 137 years of modern record-keeping

MILWAUKEE — NASA officials say May 2017 was the second-warmest May on record.

NASA’s Goddard Institute for Space Studies says May of 2017 was the second-warmest in 137 years of modern record-keeping.

Only May 2016 was hotter.

May of 2017 was just a fraction of a degree higher than the third-warmest May, which happened in 2014.

The temperature average is determined by data from more than 6,000 weather stations and other instruments around the world.

Critics have suggested warmer-than-normal temperatures are a sign of climate change.