Houston haze returns as Saharan dust, potentially affecting air quality

The heat and sun will combine with a surge of Saharan dust expected to hit Texas this week, creating a potential risk of air quality issues. Meanwhile, with rain chances virtually nil, Houston could finally get a few dry days after a very wet July so far.

At this time of year, dust from the Sahara regularly blows over Texas. It’s hard to believe that weather conditions thousands of miles away could affect us in Houston, but it does.

During the African monsoon season, which lasts until August, rain-freshened air hits the desert floor of the Sahel and kicks up dust into the atmosphere. The dust is blown off the coast of northwest Africa and travels thousands of miles across the Atlantic, floating westward on winds about a mile above the ocean surface.

Saharan dust was observed from space Monday afternoon, moving over the Gulf of Mexico. This dust is expected to spread to Texas starting Tuesday, primarily in the eastern half of the state. You will likely notice hazier skies in the Houston metro area in the afternoon. An isolated storm could develop from Houston toward the coast, but that probability is quite low.

As most of the Saharan dust settles Wednesday and Thursday, rain chances should disappear completely in southeast Texas. During this time, the haziest conditions are expected.

Typically, these Saharan dust plumes do not cause major air quality problems. But at high enough concentrations, these dusts could affect air quality.

The Texas Commission on Environmental Quality expects hourly air quality observations to reveal harmful levels of fine particles in South Texas. Closer to Houston, air quality is likely to be harmful to sensitive groups. That means if you have a chronic respiratory condition, you may notice allergy symptoms through Thursday, when the bulk of this Saharan plume arrives. Itchy, watery eyes, coughing and sneezing can all be side effects of that dusty air seeping in.

Air quality could be worse on Wednesday and Thursday, but particularly sensitive groups could experience symptoms as early as Tuesday.

As the chance of rain diminishes this week, temperatures will return to what is more typical for late July and early August.

Daily temperatures will reach a maximum of between 34 and 35 degrees, with daytime heat index values ​​exceeding 40 degrees. This is much closer to normal for this time of year. Nighttime lows will generally fall between 21 and 25 degrees each night.

The Climate Prediction Center predicts that August will be warmer and drier. Could that mean more 100-degree days? It could, especially through mid-August, as we’re in the hottest time of year climatically in Houston.