It’s not surprising Texas heat gets more intense throughout the decades, but knowing by how much proves to be difficult.
Texas heat becomes more unpleasant in a variety of ways, with higher extremes during the summer peak and toasty temperatures stretching earlier into spring.
One reader asked Curious Texas: “Since they started keeping records, how much hotter are the summers now?”
Here’s what to know about how we measure heat:
Curious Texas
Triple-digit days
The number of days reaching or exceeding 100 degrees remains a common indicator of intensity. These can vary substantially from summer to summer, but in recent decades tend to trend up.
Collection of climate data for Dallas-Fort Worth began in 1899, and since then, the area’s hottest summer, by this metric, was 2011, when 71 days hit 100 degrees or higher. The summer of 1980 isn’t far behind, with 69 triple-digit days.
The prevalence of extreme heat has fluctuated over the decades in D-FW. However, looking at Texas more broadly, a 2024 report from the Office of the Texas State Climatologist forecasts these days will continue to increase.
Average temperatures
Another way to count is the summer season’s average temperature across all of June, July and August. This incorporates overnight lows and daytime highs.
Over the last 126 years, the average temperature of sweltering summers has risen, and the “cool year” temperatures no longer dip as low. In previous decades, the average temperature of a “cool” summer was around 81 degrees, but now the “coolest” years stop at about 84 degrees.
Although it may not appear to be a large increase, these averages mask substantial variation at the extremes. This can result in record-setting heat waves, droughts and floods as extreme weather becomes more intense and more common.
These environmental shifts are primarily driven by human-caused climate change — burning fossil fuels such as coal, oil and methane gas, which creates heat-trapping pollution in the atmosphere. That activity has been the principal force reshaping our climate, but other sources of natural variability, like the El Niño Southern Oscillation, can also impact patterns.
So just how much hotter are the summers?
On the whole, it depends on how you measure the season’s “hotness.” But by almost any metric, summers increase with climate change, both dangerous to our ecosystems and livelihoods.
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