HOUSTON, Texas (KTRK) — The morning low temperature was only 82 degrees Wednesday, tying the daily record minimum temperature for July 12 in the city of Houston.
This also makes for 16 mornings in 2023 when temperatures overnight did not fall below 80 degrees. That is not normal for Houston.
Average morning low temperatures for July are in the mid 70s. And while that does not seem like much of a difference numerically, it’s still difference-making considering impacts to the rest of the day and your health.
ABC13 Meteorologist Elyse Smith spoke to Texas state climatologist, Dr. John Nielsen Gammon, about heat waves in southeast Texas and some of the factors that are leading to these frequent warmer mornings.
“There are two factors. First off, climate change has warm temperatures throughout Texas by about two degrees Fahrenheit, but also Houston itself during the summertime evenings is about two degrees warmer than the surrounding countryside. So if you’re some place like Liberty, Texas, you might be talking about how temperatures are now not dropping below 78 degrees. But 78 versus 80 actually does feel like a big difference when you’re talking about recovery time at night from a heat wave,” Nielsen Gammon said.
You should also keep in mind that with a morning temperature of 80 degrees, the heat index could already make it feel like the low 90s outside. So a future impact of these warmer mornings will be having to wake up earlier or stay up later to avoid health implications from triple-digit heat index values.
Another aspect of heat waves and warmer air temperatures is also warmer water temperatures.
“A lot of what drives our summertime temperatures is water temperatures in the Gulf of Mexico, because our air is coming basically directly from there,” Nielsen Gammon explained. “And those temperatures are going up also. And this year, in particular, they’re unusually warm in the Gulf of Mexico. And so that’s making this look like it’s going to be a fairly unusual year for 80-degree temperatures. We’re already sort of at a normal level for recent climate, and we’re still just in the middle of July.”
To that point, water temperatures in the Gulf closer to us are approaching the upper 80s, which is above normal for mid-July.
But a big headline this week has been the record-warm Gulf waters near the Florida Keys. Specifically, the water temperatures in and around the Keys are in the mid to upper 90s.
This comes after South Florida has been in a long-standing heat wave. And remember, water warms slower than air and cools slower as well, which is a potential impact that could influence hurricane season if any systems make it into the Gulf.