Texas Border Business
Texas Border Business
RIO GRANDE VALLEY, Texas — Rain and thunderstorms are expected to become increasingly likely across the Rio Grande Valley later this week, bringing a potential break from the hot and relatively dry conditions that have dominated the region.
The National Weather Service Brownsville/Rio Grande Valley office said hot temperatures will continue into late week, with afternoon showers and thunderstorms possible through Wednesday before rain chances increase Thursday and Friday.
The National Weather Service’s tabular forecast for Deep South Texas shows that rain probabilities vary by location across the Valley, meaning not every community will receive rain at the same time or with the same probability.
For Tuesday, Sept. 29, daytime rain chances are generally around 20% to 30% in parts of the region. Chances decrease Wednesday, Sept. 30, to about 10% in some locations.
Conditions are forecast to become wetter Thursday, Oct. 1. The National Weather Service forecast shows thunderstorms developing and precipitation probabilities reaching about 50% to 60% in portions of Deep South Texas.
Friday, Oct. 2, currently carries some of the week’s highest rain probabilities. The NWS forecast issued Sunday showed a 60% nighttime and 70% daytime probability of precipitation at Port Mansfield, for example. Thunderstorms were the predominant weather forecast for the area.
Thunderstorm chances continue Saturday, Oct. 3. At Port Mansfield, the NWS forecast showed a 50% nighttime probability followed by a 60% daytime chance of precipitation.
Rain also remains possible Sunday and Monday, although probabilities and shower timing could change as the week progresses.
The wetter forecast comes as the National Weather Service signals a broader transition in the region’s weather pattern. Its latest October-through-December outlook says conditions are expected to shift toward wetter and less-hot conditions after what the agency described as a very hot and dry September. The outlook calls for above-average rainfall during the closing months of 2026 while identifying flash flooding, water supply, and hazardous marine conditions as issues to watch.
Residents should keep in mind that a 60% or 70% probability of precipitation does not mean it will rain continuously throughout the day or everywhere in the Rio Grande Valley. Rain probabilities apply to specified forecast areas and periods, and conditions can vary considerably between the Upper and Lower Valley.
The National Weather Service Brownsville/Rio Grande Valley office will continue updating the forecast as the wetter pattern approaches.
Source: National Weather Service Brownsville/Rio Grande Valley.
