Last month? Hottest June on record
Pat Brennan, The Orange County Register
Last month was the hottest June ever recorded when land and sea surface temperatures are combined, a new report from the National Oceanic and Atmospheric Administration shows.
It was also the warmest on record when temperatures from April to June and January to June are averaged, the agency says.
And it’s the second warmest, after 2007, when January to June temperatures are averaged.
The average land and sea surface temperature combined for June was 61.1 Fahrenheit, 1.22 degrees above the 20th century average 59.9.
Land surface alone was also the warmest on record: 57.83, 1.93 degrees above the 20th century average.
Ocean surface temperature alone was 62.47 for June, 0.97 degrees above the 20th century average and the fourth warmest on record for June.
NOAA scientists say it was warmer than average across much of the planet, with the most intense warmth in Peru, the central and eastern United States, and eastern and western Asia.
It was cooler than average in Scandinavia, southern China and the northwestern United States.
And a drop in sea surface temperatures continued in the equatorial Pacific, matching predictions that El Niño, the periodic warming of that ocean area, was coming to an end.
NOAA says La Niña — a periodic cooling of the equatorial Pacific — is likely to develop this summer; that can lead to drier conditions in Southern California, though it’s too soon to be sure.
Although regional temperature records do not necessarily match global trends, June’s average temperature for John Wayne Airport in Orange County was very slightly higher than normal — 73.8 degrees, with a normal average of 73.6.
And on what is expected to be one of the hottest days in Orange County so far, it might be tempting to view the latest NOAA report as evidence of global warming.
While the rise in temperature is consistent with the warming predicted by most climate scientists, however, NOAA’s monthly temperature snapshots can offer little insight into long-term climate trends over decades.
A separate NOAA report declared 2009 to be the fifth warmest year on record, tied with 2006, when land and ocean surface temperatures are combined.
To understand long-term climate trends, it is more important to measure changes over decades — and those changes are clearly showing a warming trend, said Michael Prather, a UC Irvine professor who specializes in climate modeling.
“The most powerful evidence has been that whenever you do a 10-year average temperature, it’s always going up at the same rate,” Prather said. “We should be looking not for a single record, but for an inexorable rise in temperature.”
