This story is part of the KXAN Data Hub, where numbers help tell the whole story.
We’ve created several data-driven stories and databases on topics including weather and climate, politics, education, sports and growth in Texas. Each story in the KXAN Data Hub is updated as new data becomes available.
.anchor_me {
position: relative;
}
.anchor_me span {
position: absolute;
top: -120px;
}
ul.kxan_bullets {
list-style-position: outside;
}
.kxan_callout_box {
webkit-border-radius: 15px;
-moz-border-radius: 15px;
border-radius: 15px;
}
Editor’s Note: The video above shows the latest from the KXAN First Warning Weather team.
AUSTIN (KXAN) — Complete temperature records for Camp Mabry — Austin’s official reporting site — date back to 1898. Since then, Austin has reached 100° a total of 2,004 times.
The average for any given year from 1898 to 2023 is about 16 triple-digit days per year, but the data shows that number is increasing. Between 1991 and 2020, the current dates used by the National Weather Service to calculate averages, the average number of 100° days was 29.
The chart below shows the number of triple-digit temperatures recorded each year since records began.
The summer of 2011 was record-breaking. Austin hit 100° a total of 90 times that year, including a high of 112° on August 28. That ties with Sept. 5, 2000, as the hottest temperature ever recorded in the city.
The years 2023, 1925, 2009, 2022 and 1923 all saw more than 60 days of triple-digit heat.
On the opposite end of the spectrum, Austin has failed to reach 100° in 12 different years since records began, most recently in 1987.
The chart below shows the number recorded by decade.
While the 1920s and 1950s both stand out with a high number of triple-digit days, the first half of the 20th Century had relatively few days above 100°. Since the 1990s, the number has been increasing quickly. The 2000s, for example, saw 273 days at or above 100°. That number increased to 409 in the 2010s.
Austin has reached the century mark on 244 days so far this decade, meaning we’ve already hit 100° more times in just six years than the entire 1990s.
Unsurprisingly, August has recorded the most triple-digit days. The chart below shows the number of 100° days per month since records began.
Of all triple-digit days, almost half have been in the month of August, while about a third have been in July. About 12% of triple-digit days have been in June, while 7% have been in September. May and October combined account for less than 1% of all triple-digit days since 1898.
May 4, 1984, holds the title as the earliest 100° day in a calendar year. While having an incredibly early start, the year only had 18 triple-digit days in total. Meanwhile, the latest 100° on record occurred on Oct. 13, in 2024.
So which calendar day has seen 100° the most?
Aug. 10 has hit 100° a total of 42 times since records began, more than any other day. Aug. 9 is second, with 39 triple-digit temperatures.
The 30-year average for the first 100° day each year is July 4, while Aug. 30 is the average last triple-digit day of the year.