The Warmest June on Record

Globally, June 2014 was the warmest June on record for land/ocean combined surface, according to the National Oceanic and Atmospheric Administration (NOAA).

According to the NOAA report, June 2014 averaged 0.72 degrees C. (1.30 F.) above the 20th century average. Records go back to 1880.

June 2014 will also go down as the warmest June for global sea surface temperatures and the highest departure from average for any month with a temperature anomaly of +0.64 C. (1.15 F.).

What is also impressive of this record is the fact that this occurred during official ENSO-neutral conditions in the tropical Pacific. El Nino conditions are expected to officially return late in the Northern Hemispheric Summer or Fall.

The last time a month of June averaged below normal was back in 1976.

This year's January-June period was tied for third warmest on record globally.

One likely reason that the NOAA temperature anomaly for June 2014 was higher than NASA GISS is the fact that unlike NASA GISS, the NOAA dataset does not include a large portion of the polar regions. Large portions of the Arctic and Antarctic appeared to be colder than normal for June based on the GISS analysis. I blogged about the differences in analysis methods back in 2010 and wrote the following... GISS is able to extrapolate temperatures for the northern Arctic by using actual temperature data from stations farther south that are within 1200 km. GISS earlier determined that this method of estimation is actually quite accurate (small enough amount of error) in the northern latitudes.

In addition, I emailed Dr. James Hansen, the former director of NASA GISS about their method and he responded....

Brett...even though in certain cases it might be more accurate to use reanalysis rather than extrapolate observations, I prefer not to mix observations and models. Sometimes the extrapolations will be off in one direction and sometimes in another. If the weather patterns are such that there is a cool pool in the central Arctic, then our extrapolation is likely to misrepresent the situation. So I don't intend to leave the impression that I think it is accurate in individual situations, but I think that, on the average, it is better than omitting the Arctic, thus implicitly assuming that it has the same tendency as the average of all global regions with data.

Best regards, Dr. James Hansen.