I encountered two men recently who did not believe that the Earth’s climate was warming. One was a mild-mannered man from drought-stricken California, the other a vehement summer resident of Maine. “It’s all stuff and nonsense, put out by the left-wing media!” cried the latter. “You don’t really believe that the entire atmosphere has changed?” asked the former, eyebrows raised high on his forehead. 

Well, yes, in fact, I do. This tidbit of information, released last week by the federal National Oceanic and Atmospheric Administration, might persuade these two men as well. It turns out that this June was the warmest June since global temperature records began in 1880, surpassing June 2015, which held the record up to this year. It was the 14th consecutive month that the average global (comprising land and sea surface temperatures) temperature record was broken, making it the longest streak of hot months in 137 years. That’s a significant milestone in itself, but even more important is the fact that this was the 34th consecutive warmer-than-average June. 

Let’s see, that means that way, way back in 1982 we experienced a June with a normal temperature (59.9°F was the average June temperature for the 20th century). When I say “we” I mean the world as a whole. Climate is what happens to the planet over time, not what occurs in Rockland or Maine in a given year. So back in the dim and distant past, in the time of Ronald Reagan, “Conan the Barbarian,” and padded shoulders in ladies’ wear, the majority of the Earth’s population probably had a pleasant June.

What was our current June like?

Globally, this June was 1.62°F warmer than average, and 0.04°F above last year’s record-breaking June. In North America, it was the warmest June on this continent since records began in 1910. The extent of the Arctic sea ice was 11.4% below the 1981–2010 average. That is the smallest expanse of ice seen since scientists began tracking it in 1979, 100,000 square miles smaller than the previous record set in 2010.



For the entire globe, the average land surface temperature was 2.23°F above the 20th-century average of 55.9°F. That is the same temperature as in 2015, which was itself the highest June land temperature since 1880. 

The average sea surface temperature was 1.39°F above the 20th-century average of 61.5°F, the highest global ocean temperature for June since 1880. 2015 was, of course, the previous record-holder. June was the 40th consecutive June with global ocean temperatures above 61.5°F. 

And it wasn’t just June that was warm. From January to June, the global temperature was 1.89°F above average. This was the highest temperature for that period ever, surpassing — you guessed it — the previous record set in 2015. The average land surface temperature for that period was 3.17°F above the previous century’s average temperature of 45.0°F. This was the highest temperature since 1880, exceeding 2015’s record high temperature by 0.7°F.  

We all know that it has been extremely hot in the Midwest this summer, due to the ominously named “heat dome” parked over the nation’s midlands. But temperatures in that part of the country have been rising steadily for more than 100 years. According to the 2014 National Climate Assessment, the average temperature in the region increased by more than 1.5°F between 1900 and 2010. Between 1950 and 2010, the rate of increase doubled. Since 1980, that warming rate is three times faster than between 1900 and 2010.

I would like to say to the two gentlemen mentioned earlier:  Want to place your bets on what records this July will break?