By Climate Central
The summer doldrums have set in for much of the U.S., but an end to the Dog Days of summer is within sight. The Dog Days traditionally extend from July 3 to August 11, when Sirius (aka the Dog Star) rises and sets with the sun. Ancient cultures believed that additional energy from Sirius helped make the summer days hotter, but in modern times, the addition of greenhouse gases in the atmosphere is giving summer temperatures a boost. To complement last week’s analysis examining the number of very hot days a year, we examined the consecutive number of very hot days each year. Since the term heat wave has a different meaning in different climates, we refer to these as heat streaks.
Number of extremely hot summer days in these U.S. cities
Not surprisingly, the analysis yields a similar theme as our extremely hot days analysis, with 75 percent of the 244 cities analyzed having longer heat streaks than a half-century ago. The length of these heat streaks has increased the most in Texas cities, with the longest streaks above 95°F in Houston and San Antonio each averaging more than 10 days longer. Several Southeastern cities are not far behind. Shreveport, Louisiana and Huntsville, Alabama each have heat streaks above 95°F averaging a week longer.
Methodology: Data was gathered from the Applied Climate Information System. To determine the threshold temperature for each city, we used the highest daily temperature (at 5°F intervals) with an average of at least one 5-day streak at that value per year during the analysis period.