Summer doesn’t officially start until June, but Central Texas temperatures flirted with the 100-degree mark throughout the Memorial Day weekend.
Austin’s main weather station at Camp Mabry hit 96 degrees Monday and got as hot as 99 Saturday, but only the heat index reached triple-digit values because of the elevated humidity.
So when should we expect temperatures to break that 100-degree barrier this year? Probably sometime this week, according to the National Weather Service’s extended forecast. That’s still a lot sooner than normal, even as global temperatures continue to rise.
Based on National Weather Service data going back to the 1890s, Austin normally sees its first 100-degree day around July 10 and will, on average, see triple-digit temperatures persist until Aug. 21. The city averages about 14 days of triple-digit temperatures each year, the data show.
But if you look at just the numbers since 1998, as the effects of climate change have become more apparent, the annual average number of days with 100-degree weather climbs to 32. The first 100-degree day arrives a little earlier, around June 28. The triple-digit temperatures continue farther into the calendar, with the last day of 100-degree weather, on average, occurring Sept. 2.
Austin has experienced this kind of extreme heat as early as May 4 — it hit 100 degrees on that date in 1984 — and as late as Oct. 2 — it hit 100 in 1938. Fun fact: Oct. 2, 1938, also was the only day Austin had triple-digit temperatures that year.
Last year, the warmest year on record in Austin, had its first day of triple-digit temperatures June 17. The next month, temperatures were 100 degrees or hotter for 24 of July’s 31 days.
Last summer, the city withered under 100-degree weather for 42 days until Aug. 23. The hot streak was snapped by the arrival of storms associated with Hurricane Harvey, which made landfall on the Texas Gulf Coast two days later.
During 2011 — the year with a record-setting 90 days of triple-digit temperatures — the first 100-degree day came as early as May 25. In July and August that summer, 29 of each month’s 31 days saw maximum temperatures of 100 degrees or more.
The oppressive heat that compounded a historic drought in 2011 lasted nearly into October. Temperatures reached 105 as late as Sept. 25, but the last day of triple-digit temperatures was Sept. 29, when it hit 101.
Although the 100-degree mark remains psychologically important for those of us in Central Texas who are sweating it out, meteorologists are more worried about the physical dangers of such extreme heat, such as dehydration, heat stroke and other heat-related illnesses.
Even with temperatures still in the 90s, forecasters say residents should watch for signs of heat exhaustion, such as nausea, dizziness or flushed skin.
As of Saturday, Austin-Travis County Emergency Medical Services officials said medics had responded to at least 18 heat-related incidents in the past week.
If you’re outside, schedule frequent breaks in the shade or indoors, drink plenty of water, and never leave small children or pets in vehicles, where interior temperatures can reach deadly levels in minutes.
“We try to focus on safety, so when we get into these high-temperature days, it does mean something,” weather service meteorologist Yvette Benavides said.