The summer of 2010 is going into the record books as the hottest summer in North Alabama since 1954 — the third time that has happened in the past five summers, according to data from Alabama’s climatologist.

Through Wednesday, the area’s daily high temperatures since June 1 averaged 93.86 degrees Fahrenheit. With forecast highs through the end of the month cooler than that, this summer should finish as not more than the 8th hottest summer in the past 118 years. The summer of 1930 was the hottest since 1893, with average daily high temperatures of almost 95.4 degrees.

“If you look at the summer temperature trend over the past century, this summer stands out,” said Dr. John Christy, Alabama’s state climatologist and a professor of atmospheric science at The University of Alabama in Huntsville. “North Alabama summers were much warmer from 1900 through 1954. No one knows why, but summer temperatures dropped noticeably after 1954. For instance, from 1958 through 1977 there was only one summer where the average high temperature was above 90 degrees. From 1955 to 2005, none were above 92 degrees.

“In terms of a trend, summer temperatures in this area didn’t do much of anything from 1955 until very recently,” he said. “Now three of the past five summers — 2010, 2006 and 2007 — have been the warmest in 50-plus years.

“That isn’t enough to say there has been a shift in our weather patterns, but it does make you wonder if the temperatures recorded in the first half of the 20th century are what is ‘normal’ for summer in this region. If that’s the case, we might see more summers like 2010 in the next several years.”

Daily high temperatures give a better indication of long-term climate trends and better represent the natural climate because the daytime mixing of the atmosphere helps overcome the temperature effects of local urbanization, deforestation and farming, Christy said. Nighttime temperatures at the Huntsville International Airport and UAHuntsville, which are influenced more by human development, routinely show temperatures that are artificially warmer than those in the surrounding countryside. That means readings at urban stations aren’t representative of the broader surroundings at night.

“That’s why reports which talk about the average of the daytime high and nighttime low, based on a station with development around it like the Huntsville Airport, won’t reflect the natural climate,” Christy said. “But for people who pay utility bills, that extra urban heat is real.”

The current temperature data for Madison, Limestone and Morgan counties is collected at seven stations: the Huntsville International Airport, Decatur, the UAHuntsville campus, Owens Cross Roads, Belle Mina, Pryor Field airport in Limestone County, and Athens.

Historic data was also collected at weather stations in downtown Decatur, Maysville, Coldwater, TN, Falkville, Madison, New Market, downtown Huntsville, the old Huntsville Airport, a station that was two miles south of Athens, and at two stations on Redstone Arsenal.

North Alabama’s 12 Hottest Summers

1.  1930 – 95.39

2.  1952 – 94.93

3.  1954 – 94.93

4.  1943 – 94.89

5.  1925 – 94.82

6.  1936 – 94.78

7.  1902 – 94.10

8.  2010 – 93.86*

9.  1932 – 93.76

10. 1934 – 93.73

11. 1931 – 93.63

12. 1921 – 93.33