Air temperature along with humidity can be fatal. Houston’s days with an air temperature above 95 degrees plus its humidity plus the heat retained by concrete and asphalt results in life-threatening events for people and pets.
House Buyers in Houston are asking more and more questions about the heat during the summer season. They ask about electrical costs to cool their homes and what can be done to reduce these costs. We talk about small and big changes they can make to their newly purchased homes that will improve energy efficiency. Trees and plants provide shade that can be a big help. If a roof has to be replaced we suggest asking the roofing contractor about the new technology available in roof materials, roof paint, and thermal barriers. Double or triple window panes, window coverings, and overall house insulation can be very beneficial. And ceiling fans are a great idea for any Houston area home. Ceiling fans help circulate cool air and makes the living environment cooler.
July 2023 Was Hottest Month In World History
NASA scientists confirmed that July 2023 was the hottest month in the recorded history of global temperature. In addition, the five hottest Julys since 1880 have all occurred in the past five years. Their report urged people and politicians to act now to protect the planet. The report specifically mentioned clean energy manufacturing and steps to make communities more climate resilient.
Scientists have studied how the combination of heat and humidity can prove fatal. They have defined a “wet bulb temperature” which is the point where the sweat from a human body will not evaporate off the skin, which will lead to heatstroke and death. It is estimated that a young healthy person will die in six hours in an outdoor environment of 95 degrees and 100% humidity. Other research suggest death will occur much sooner than six hours. The very old, very young, and less healthy can endure far less time in this heat and humidity environment. Higher temperatures and less humidity can result is similar dangerous conditions.
Lethal “wet bulb” events are becoming more common around the world and in Houston. However, temperatures and humidity below the “wet bulb” threshold can be dangerous. Older people have fewer sweat glands and therefore are less able to cool their core body temperatures. They greatest number of heat-related deaths in is the older population.
How Hot Is Houston ?
The highest temperature ever recorded at George Bush International Airport in Houston was 109 degrees on four different dates in 2000, 2011, and twice in 2023. The hottest month on record in Houston was August 2023 according to the National Weather Service. The average temperature was 91.0 which was almost 6 degrees higher than the average temperature for August. The hottest Houston summer on record was also recorded in 2023. That year Houston had 45 days with temperatures of 100 degrees or higher. Globally, the average temperatures have been rising for the past 30 years and Houston can expect more heat in the coming years.
Another method of measuring the heat in cities is by counting the number of days when the temperature is 95 degrees or higher. When the temperature hit 95 or more it is considered a “hot” day. A study by the International Institute For Environment And Development used a 47 year time period starting in 1976 and ending in 2023. Seven of the top ten cities were in Texas. Houston was number 3. Below are the statistics – the number of “hot” days in the top ten cities beginning in 1976 to 2023.
Cities With Big Increase In Number Of Hot Days During Summer (95 F or more)
| City | 1976 | 2023 | Increase |
|---|---|---|---|
| San Antonio | 7 | 96 | 89 |
| Austin | 19 | 88 | 69 |
| Houston | 11 | 73 | 62 |
| Tucson | 79 | 132 | 53 |
| Fort Worth | 37 | 73 | 35 |
| Arlington | 46 | 80 | 34 |
| Fresno | 60 | 92 | 32 |
| El Paso | 62 | 89 | 27 |
| Dallas | 46 | 72 | 26 |
| Denver | 5 | 31 | 26 |
Source: International Institute For Environment And Development
Stated another way, Houston had 11 days of extreme heat in 1976. In 2023 it had 73 days of extreme heat. Unfortunately for Houston, and many other cities, the trend is for more days of extreme heat in the future.
Cities With Greatest Number of Hot Days During Summer (95 F or more)
| City | Number Of Hot Days |
|---|---|
| Phoenix | 158 |
| Mesa, AZ | 141 |
| Tucson | 132 |
| San Antonio | 96 |
| Fresno, CA | 92 |
| Bakersfield, CA | 90 |
| El Paso | 89 |
| Austin | 88 |
| Arlington, TX | 80 |
| Houston | 73 |
| Fort Worth | 73 |
| Dallas | 72 |
Source: International Institute For Environment And Development
Heat Danger In Other Cities
Other cities in the country are experiencing scorching temperatures in 2024. Las Vegas had a very memorable July 2024 with temperatures above 105 degrees every day. The hottest day was 120 degrees.
San Antonio has seen a huge increase in the number of very hot days. The 2024 summer is not over but so far the city has experienced 54 days with temperatures of 95 degrees or higher.
The Urban "Heat Island" Effect
The urban heat island effect results from the fact that buildings, roads, concrete sidewalks radiate significant heat during hot days. This radiated heat can add 20 degrees to the temperature of an urban environment. To some degree, this can be mitigated by planting more trees and grass when possible.
The country's 50 largest cities have all recorded hotter average temperatures over the past 47 years. Of the 50 cities, all but 3 have experienced more hot days above 95 degrees. The 3 exceptions are Los Angeles, Omaha, and Kansas City.
Can Houston Adapt To Future Heat Increases ?
Housing demand in the Houston is strong and has been for a long time due to the employment opportunities. Potential home buyers are seeking affordable housing that is energy efficient. That places a burden on home builders because they will have to build houses with different features and new technology to achieve high levels of energy efficiency.
Some of the new design features in new Houston area homes may be:
- simple, compact shapes are more energy efficient because they have smaller surface areas and less exposure to the sun
- house orientation; houses built with a long axis running east-west will minimize exposure to the sun's rays; fewer windows should be located on the south side of the house
- insulated and ventilated roofs; roof vents
- natural ventilation; cross-ventilation, skylights, courtyards, and atriums
- shade; awnings, shaded porches, wrap-around porches; overhangs; louvres; screens; trees planted on the west and south sides of homes and buildings
- green building features including rain gardens, green roofs, and living walls; these feature provide natural insulation and provide evaporative cooling through transpiration
- heat pumps for heating and cooling homes
- energy efficient appliances such as induction stoves and induction clothes dryers