The highest air temperature ever officially recorded in Texas is 120 °F (48.9 °C), measured at Seymour in Baylor County on August 12, 1936, during the catastrophic Dust Bowl drought. That single-day figure, later tied at Monahans in 1994, still stands as the state’s all-time record. But a single thermometer reading only tells part of the story, because what counts as “hottest” depends on whether you mean one afternoon at one weather station, an entire summer averaged across the state, or the punishing combination of heat and humidity that determines how dangerous the air actually feels on your skin.
The 1936 Record and the Dust Bowl
Seymour sits in north-central Texas, about halfway between Wichita Falls and Abilene, in rolling ranchland that was already parched by years of drought when the thermometer hit 120 °F in August 1936. That summer was brutal across the entire Great Plains. Bare, over-farmed soil had lost its ability to hold moisture, and without evaporating water to cool the surface, the ground essentially became a griddle radiating heat back into the air. The same physics that made the Dust Bowl so deadly for crops also made it the perfect incubator for record air temperatures.
Nearly six decades later, Monahans in far West Texas tied that 120 °F mark on June 28, 1994, during a severe regional heat wave. Monahans sits in the Permian Basin at around 2,600 feet elevation, where low humidity and sparse vegetation allow afternoon temperatures to soar. The fact that Texas’s two highest readings occurred in very different landscapes, one in eroded prairie and the other in arid desert, reflects just how many ways the state’s geography can conspire to produce extreme heat.
The Summer of 2011 and Statewide Records
While Seymour holds the single-day record, the summer of 2011 was almost certainly the hottest summer Texas has experienced as a whole when you average conditions across the entire state over an extended period. From June through August 2011, the statewide average temperature broke records that had stood since the 1930s. Dallas-Fort Worth logged 71 days at or above 100 °F. Wichita Falls hit 100 °F for 100 consecutive days. Statewide, the drought that accompanied this heat was the worst single-year drought in Texas’s recorded history, with agricultural losses estimated in the billions of dollars.
Researchers have examined whether this kind of summer could have happened without the warming influence of greenhouse gas emissions. A study using large climate model ensembles found that anthropogenic forcing significantly increased the probability of Texas experiencing a summer as hot as 2011, compared to a hypothetical world still at preindustrial greenhouse gas levels.1Geophysical Research Letters. Anthropogenic influence on the changing likelihood of an exceptionally warm summer in Texas, 2011 The drought itself was a major contributor to the heat, but the background warming made the event more likely to occur and more intense once it arrived.
The 2023 Heat Wave and the Heat Index Question
If you shift the question from raw air temperature to what the heat actually feels like, 2023 introduced a new dimension. That summer, Houston’s Ellington Airport recorded a heat index of about 167 °F (75 °C) on July 23, a figure that reflects the combined effect of high air temperature and oppressive humidity. The heat index is what meteorologists use to communicate how hot conditions feel to the human body, because humid air prevents sweat from evaporating, which is your main cooling mechanism. When humidity is high enough, even air temperatures in the low 100s can produce heat-index values that are genuinely life-threatening.
An analysis of the 2023 Texas heat found that global warming of roughly 1.5 °C increased the highest heat-index readings during that June-through-August period by an average of about 5 to 6 °C (roughly 8 to 11 °F). That Houston heat-index peak, for example, would have been around 6 °C lower without the warming that has already occurred, bringing it down to roughly 156 °F instead of 167 °F.2Environmental Research Letters. Heat index extremes increasing several times faster than the air temperature The critical takeaway is that heat-index extremes are climbing several times faster than air temperature alone, because warming air holds more moisture, and the heat index responds nonlinearly to that combination. A modest rise in average temperature translates into a much larger rise in felt heat when humidity is already high.
Why Drought Makes Texas Heat Worse
Texas heat waves are almost always tangled up with drought, and the two reinforce each other in a feedback loop that makes both worse. When soil dries out, less water evaporates from the surface, and evaporation is one of the main ways the land sheds heat. Without it, more of the sun’s energy goes directly into heating the air. The surface essentially stops sweating. This shift toward heating rather than evaporating, measured by scientists as an increase in sensible heat flux, can add several degrees to afternoon temperatures during a drought compared to a summer with normal soil moisture.3Communications Earth & Environment. Soil moisture−atmosphere feedbacks have triggered the shifts from drought to pluvial conditions since 1980
The hotter it gets, the more moisture the atmosphere demands from the soil and vegetation, which dries the ground further, which heats the air further. Modeling of the 1998 Oklahoma-Texas drought showed that this regional feedback between lower evaporation and reduced precipitation played a substantial role in sustaining the drought once it was established.4Nature. Role of sea surface temperature and soil-moisture feedback in the 1998 Oklahoma–Texas drought In other words, the drought locked itself in. Sea surface temperatures in the tropical Pacific set the stage by steering weather patterns that reduced rainfall over Texas, but local land-surface drying amplified and prolonged the event well beyond what the ocean signal alone would have produced.
This same mechanism was in play during both the 1930s Dust Bowl and the 2011 drought. It is one reason Texas heat records tend to cluster in drought years rather than in years with normal rainfall. A wet spring, by contrast, can keep soils moist enough to blunt summer temperatures even when large-scale weather patterns favor hot conditions.
The Gulf of Mexico Connection
Texas sits next to one of the warmest bodies of water in the western hemisphere, and the Gulf of Mexico plays a dual role in the state’s heat story. On one hand, moisture streaming off the Gulf feeds humidity into eastern and coastal Texas, driving up the heat index and making nights miserable. On the other hand, in years when the Gulf is abnormally warm, it pumps even more moisture and heat into the atmosphere.
In 2023, the Gulf of Mexico experienced record-high sea surface temperatures, and researchers found a strong correlation between those ocean temperatures and the extreme heat that settled over Texas and Louisiana that summer. The relationship was especially pronounced for overnight low temperatures, which is consistent with the idea that a hotter Gulf keeps pumping humidity and warmth onshore even after the sun goes down.5Environmental Research: Climate. A rapid response process for evaluating causes of extreme temperature events in the United States: The 2023 Texas/Louisiana heat wave as a prototype High overnight temperatures matter for public health because they deny the body its recovery period. People can tolerate very high daytime heat if nights cool off enough to allow rest, but when the low temperature stays in the mid-80s or above, heat illness and death rates climb.
West Texas, by comparison, is largely cut off from Gulf moisture by distance and terrain. There, extreme heat tends to come with low humidity, classic dry desert heat. That makes for higher raw air temperatures but lower heat-index values. The same 110 °F in Midland feels very different from 100 °F in Houston, even though the Houston reading can be more physiologically dangerous.
Urban Heat in Texas Cities
If you live in one of Texas’s big metro areas rather than in rural ranchland, the temperatures you experience are likely higher than what the nearest official weather station records, because cities create their own heat. Pavement, rooftops, and concrete absorb sunlight during the day and radiate it back at night, creating an urban heat island that can be several degrees warmer than surrounding countryside.
A spatial analysis of the Dallas-Fort Worth region using gridded temperature data and satellite-derived maps of impervious surface area confirmed that urban-rural temperature differences grew as the proportion of paved and built-over surfaces increased.6Urban Climate. Application of spatially gridded temperature and land cover data sets for urban heat island analysis The more concrete and asphalt surrounding a measurement point, the warmer it was compared to nearby rural areas. This effect is strongest at night, because developed surfaces retain heat long after sunset while open soil and vegetation cool off relatively quickly.
In practical terms, this means that people in inner-city neighborhoods in Houston, Dallas, San Antonio, and Austin routinely experience heat that is meaningfully worse than the headline temperature you see on a weather app, which is typically measured at an airport or other relatively open site. Older, denser neighborhoods with less tree canopy and more dark roofing bear the brunt of this. During the most extreme heat waves, the difference between an affluent, tree-lined suburb and a heat-absorbing urban core can be the difference between uncomfortable and dangerous.
Has Texas Always Been This Hot
Extreme heat in Texas is not new. Paleoclimate research using tree-ring records and sediment cores from the northwestern Gulf Coast has extended the drought record for the region back roughly 3,000 years. That extended record shows cycles of intense drought and relative wetness corresponding to well-known climate periods, including the Medieval Warm Period and the Little Ice Age, driven largely by shifts in North Atlantic sea surface temperatures.7ScienceDirect. Drought modulated by North Atlantic sea surface temperatures for the last 3,000 years along the northwestern Gulf of Mexico During the Medieval Warm Period, roughly 900 to 1300 CE, parts of the Southern Plains experienced droughts that were longer and in some cases more severe than anything in the instrumental record.
This means the Dust Bowl, devastating as it was, may not have been the worst drought Texas has endured over the last few millennia. It was the worst since Europeans began keeping weather records, but the tree rings suggest that earlier droughts could rival or exceed it. The difference today is that modern heat events are occurring on top of a warmer baseline. The atmosphere is roughly 1.1 to 1.2 °C warmer globally than in the pre-industrial era, and that background warming loads the dice toward more extreme peak temperatures and, especially, more extreme heat-index values during any given drought.
How Heat Records Get Measured and Why Some Are Disputed
When people ask about the hottest temperature ever recorded in Texas, the answer depends on which records you trust. The Seymour reading from 1936 is the one recognized by NOAA and the Texas State Climatologist, but weather observation in the 1930s was considerably less standardized than it is today. Stations used liquid-in-glass thermometers housed in wooden shelters, and siting varied from station to station. Some early observation sites were positioned near buildings or on bare soil in ways that would not meet current standards.
None of this means the 120 °F reading is wrong. It means that comparing it directly to temperatures measured by modern automated stations, which use electronic sensors inside standardized aspirated shields at precise heights above maintained grass surfaces, involves some apples-and-oranges uncertainty. This is a well-known issue in climate science more broadly, and it applies to all-time temperature records across every state, not just Texas. Researchers routinely account for these instrumentation differences when constructing long-term temperature trends, but the all-time-record game by definition lives or dies on individual station readings taken at specific moments, with whatever equipment and siting existed at that moment.
Modern mesonet stations and automated weather observing systems across Texas now provide a far denser and more consistent picture of temperature extremes than was available in the 1930s. Whether the true hottest temperature to ever occur somewhere in the state exceeded 120 °F on some unmonitored patch of West Texas desert is something we simply cannot know. The record is the hottest temperature that was measured, not necessarily the hottest temperature that ever happened.
What “Hottest” Means Going Forward
The distinction between raw air temperature and felt heat is increasingly important for Texans. The state’s all-time air temperature record of 120 °F could conceivably be broken in a future drought, especially in the arid west where dry-bulb temperatures have the most room to climb. But for the roughly 24 million Texans who live in humid eastern and coastal regions, the more relevant danger is the heat index, which is rising far faster than the thermometer alone. A summer that does not break any air temperature records can still break heat-index records and strain hospitals.
Overnight lows are another metric that matters more than most people realize. Several Texas cities have seen their warmest overnight low temperatures shatter records in recent years. San Antonio recorded its warmest overnight low on record in July 2023, and multiple Gulf Coast stations reported overnight lows that stayed above 85 °F for consecutive nights. Research on the 2023 heat wave found that the Gulf of Mexico’s record sea surface temperatures were a major driver of these elevated nighttime readings.5Environmental Research: Climate. A rapid response process for evaluating causes of extreme temperature events in the United States: The 2023 Texas/Louisiana heat wave as a prototype As ocean temperatures continue to warm, this pattern is expected to intensify, making future Texas summers more dangerous even on days when daytime highs are not themselves record-breaking.
The drought-heat feedback that amplified the 1936, 1998, 2011, and 2023 events has not gone away. If anything, its potential to produce extreme temperatures is increasing because each drought now starts from a warmer atmospheric baseline. A repeat of 1930s-level soil conditions combined with present-day greenhouse gas concentrations would almost certainly produce statewide average temperatures exceeding what was recorded in 2011, and localized peaks that could challenge or surpass the 120 °F mark. Whether the state’s official record falls in any given year is partly a matter of whether a thermometer happens to be sitting in the right spot at the right moment, but the odds of that alignment are growing.