Does an early-season heat wave mean San Antonio, Texas Hill Country will have a very hot summer?

The average high temperature from mid-May to early June is in the upper-80s. Needless to say, it’s been much hotter than that. Afternoon temperatures have consistently been above 95 degrees with heat index values well into the triple-digits.

No doubt that it has been a rude awakening to the summer months ahead. But there’s one question I’ve been getting out and about around town: Does this mean we’re going to have a brutally hot summer?

Let’s chat about it.

KEY POINTS:

• Summers have been and will always be pretty hot in San Antonio

• A hot May DOES NOT necessarily mean we’re going to have an extremely hot summer

• Summer 2024 has a 50-60% chance of being at least somewhat hotter than average

• Tropical activity has a BIG impact on summer rainfall and temperatures

A hot May DOES NOT mean we’ll have a very hot summer

While warmer than average, hot weather in May is not unusual for the San Antonio metro area.

Since 1980, about a third of days in May have had a high at or above 90 degrees, with about a tenth of days featuring a high at or above 95 degrees.

So, a few 90+ degree days are not out of the ordinary. But what about if May is much hotter than average? Does that mean we’ll have a very hot summer?

No, it doesn’t. Take a look at the chart below. It compares our hottest summers to the May of that year. As you can see, there’s no major correlation between a very hot summer and the weather in May. The only years with a hot May and a record hot summer have been 2022, 2018 and 1998. Seven out of ten years with a record summer had mild — or even cool — Mays.

What will Summer 2024 look like?

The National Weather Service forecasts that our region of Texas has a 50-60% chance of being hotter than average. That doesn’t mean it’s going to be the hottest summer ever. Just that there’s a good chance it’ll be at least somewhat hotter than the average.

As for rainfall, the NWS is forecasting equal chances of a dry or rainy summer. In short, rainfall this summer could go either way.

So, what’s the average for our summer? Here’s a chart of averages for the summer months — defined as June, July, and August.

The X-Factor: tropical storms

There’s one BIG thing that can throw off these National Weather Service forecasts for summer…tropical storms and hurricanes.

Around San Antonio, we rarely see devastating direct impacts of destructive winds and storm surge from tropical systems like in Houston, Galveston, and Corpus Christi.

Rather, this far inland, if a tropical storm makes landfall along the Gulf Coast and heads our way, it usually just means increased rainfall, cloudier skies, and cooler temperatures – especially if the tropical storm is unorganized and weak.

In fact, officials with the National Oceanic and Atmospheric Administration (NOAA) released their seasonal outlook on Thursday, in which they stated that an ‘above-normal’ season is expected.

Forecasters cite that near-record warm ocean temperatures, lower trade winds and less shear in the Atlantic, along with the development of La Niña conditions in the Pacific could lead to more tropical activity.

This does not necessarily mean that an above-average number of landfalls will take place in the United States, but all it takes is one storm to skew our local forecast to rainier, cloudier, cooler.

No matter what this summer brings, you can count on Your Weather Authority to keep you safe and informed!