Last month was the fourth warmest May on record, two reports out today agree

Here's how surface temperatures around the globe in May varied from the long-term average for the month. Last month was the fourth warmest May globally on record. (Source: NASA/GISS) In their monthly climate reports released today, both NASA and NOAA agree that last month was fourth warmest among all Mays dating back to 1800. This means that the period 2014 through 2018 has brought the five warmest Mays in 138 years of record-keeping, according to NOAA's report. The warmest was May 2016. "May 2018 also marks the 42nd consecutive May and the 401st consecutive month with temperatures, at least nominally, above the 20th century average," according to NOAA.