CORPUS CHRISTI, TX — There are a few reasons why September is typically the wettest month on record for the Coastal Bend. Some of those include the peak of hurricane season, moisture from the Gulf, cold fronts, and more organized systems.
First, we take a look at our average rainfall in Corpus Christi throughout the year and September brings in the highest value at 5.42 inches.
1. Peak of Hurricane Season
- September is the climatological peak of the Atlantic hurricane season (Sept. 10 on average).
- The Gulf is at its warmest this time of year (often 85–88°F), providing fuel for tropical storms and hurricanes.
- Even if a storm doesn’t make landfall, tropical systems nearby can bring heavy rain bands or enhance moisture flow.
2. Gulf Moisture is at its Maximum
- Warm Gulf waters lead to very high evaporation rates, which loads the atmosphere with humidity.
- Winds from the southeast bring that moisture inland. When it lifts (from sea breezes or passing disturbances), it easily turns into showers and thunderstorms.
3. Cold Fronts Begin to Appear
- Early fall is when the first weak cold fronts begin dipping into South Texas.
- These fronts stall or slow near the coast, interacting with rich Gulf moisture.
- The combination of tropical humidity + lifting from fronts = widespread rain events.
4. More Organized Rainmakers
- Unlike the hit-or-miss summer sea breeze showers, September often brings larger, more organized systems — tropical waves, stalled fronts, or remnants of storms — which produce soaking rains over wide areas.
5. Local Geography
- The Coastal Bend’s position along the Gulf makes it especially vulnerable to tropical inflows.
The National Weather Service observed the average rainfall from last September, Corpus Christi recorded 6.47 inches. When comparing this map to the average monthly rainfall map, more rain was received throughout the Coastal Bend in September 2024.
Within the next 6-10 days, the Climate Prediction Center estimates that south Texas will generally be between normal and drier on average. We will continue to monitor the tropics for any development that could heighten our rain chances headed into the weekend as well as the remainder of September.