Each month this year, climate data have shown one of the warmest starts to any year on record, and that continued in September across the country and state and in Baltimore.
Across the contiguous U.S., January through September was the warmest first nine months of a calendar year on record, with an average temperature of 59.8 degrees. The average temperature in September was 67 degrees, tying September 1980 as the 23rd warmest on record.
In 25 states, including Maryland, it has been the warmest start to a year on record. The other states are largely along the East Coast and across the nation's heartland in the Midwest. Only in the Pacific Northwest has it not been among the top five warmest years on record, according to this NCDC map.
In Baltimore, the average temperature from January through September has been 62.2 degrees, as measured at BWI Marshall Airport. It's the first time since record-keeping began in 1871 that the average temperature through that period has topped 62 degrees. The average temperature through September reached 61 degrees in 1949, 1921, 1930, 1939, 1991, 1933 and 1932.
Last month's average global temperature of 60.21 degrees tied with September 2005 as the warmest since record-keeping began in 1880, according to the National Climatic Data Center.
Temperatures were unusually warm across Canada and parts of the western U.S., in eastern Europe, central Russia and in Japan and the Pacific Ocean waters to its east. There were still cold pockets in Siberian Russia, Alaska and Southern Africa, though. View the temperature anomalies on this NCDC map.
Arctic sea ice reached its smallest extent in 34 years, at 1.32 million square miles on Sept. 16. Antarctic sea ice, on the other hand, reached 7.51 million square miles on Sept. 26, the largest area on record.
Across much of the U.S., at least, warmer-than-normal temperatures could continue through the end of the year. The Climate Prediction Center is calling for at least a one in three chance of above-average temperatures across most of the country. For the upper Midwest and Northeast, including parts of Maryland, the chances are higher, at about 40 percent, according to seasonal outlook maps.