September continued the hot and dry pattern across much of North Texas. DFW Airport recorded an average temperature of 87.9°F, 9.4°F above normal, making it the hottest September on record and surpassing the previous record set in 2019 by 2.4°F. DFW received only 0.17 inches of rainfall, compared with the September normal of 2.72 inches.
Rainfall across TRWD’s watersheds varied during September. The Lake Bridgeport and Eagle Mountain Lake watersheds received 4.2 and 3.8 inches, respectively, both above normal for the month. Farther east, the Cedar Creek and Richland-Chambers watersheds received only 1.5 and 1.2 inches, respectively.
Although the TRWD watersheds received much-needed rain in September, most of it was absorbed by dry soils and was insufficient to fully offset ongoing evaporation, water demands, and cumulative drought impacts. As a result, combined system storage declined from approximately 83.7% on September 1 to 80.4% on October 1.
What to Expect: As we move into October, cooler seasonal temperatures should begin to reduce evaporation and water demands. Based on current conditions, lake levels are expected to generally follow the “Normal Rainfall” trends represented by the green shaded areas on the Lake Level Projection Plots, with the potential to trend toward the “Above Normal” blue shaded areas if wetter conditions develop. Following prolonged dry conditions, additional rainfall may initially soak into dry soils before producing more substantial runoff to the reservoirs. As soils become wetter, subsequent rainfall would be more likely to generate runoff. Combined with lower seasonal evaporation rates and reduced water demands, these conditions should help stabilize lake levels and support reservoir recovery if wetter conditions develop.
September Highlights:
- Temperature: September was exceptionally hot across North Texas. Temperatures reached 100°F or higher on 15 days during the month. Record-setting heat contributed to continued high evaporation and water demands across the region.
- Rainfall: Rainfall across TRWD’s watersheds varied, ranging from 4.2 inches at Lake Bridgeport to 0.9 inches across the Fort Worth Floodway.
- Drought Conditions:
- Drought conditions worsened substantially across North Texas during September, with Extreme Drought (D3) developing in portions of the region and Severe Drought (D2) becoming widespread.
- View the latest conditions on the NWS Drought Monitor.
Looking Ahead:
- ENSO Conditions: El Niño continues to strengthen. NOAA’s Climate Prediction Center indicates a greater than 90% chance of a very strong El Niño during fall and winter 2026–27, with a 75% chance that the October–December event reaches a strength exceeding previous El Niño events dating back to 1950.
- Rainfall: The October outlook favors above-normal precipitation across portions of Texas, including increased odds across much of southern and eastern Texas. The October–December outlook also favors above-normal precipitation across a broad portion of Texas.
- Temperatures: The October temperature outlook shows equal chances of above-, near-, or below-normal temperatures across North Texas. The October–December outlook also indicates equal chances of above-, near-, or below-normal temperatures across the region.
- Looking Further: A strengthening El Niño remains an important factor heading into fall and winter. El Niño can favor wetter conditions across Texas during the cool season, but it does not guarantee above-normal rainfall at any particular location. Reservoir projections will continue to be updated as rainfall patterns and seasonal conditions develop.
*Note: ENSO, or the El Niño-Southern Oscillation, is a recurring climate pattern that influences global weather. It has two main phases: El Niño, which often brings wetter conditions, and La Niña, which typically leads to drier and warmer weather in Texas, especially during fall and winter. This shift is important for water resource planning, as it can affect rainfall and reservoir levels.
Stay Informed by Checking Out the Following:
- TRWD’s quarterly watershed protection newsletter, The Tributary.
- The latest Lake Level Projections (see below).
- Links to historical lake level plots.
- Past projections compared to actual outcomes.
Thank you for following the Lake Level Blog. Check back next month for more updates!
TRWD Watershed Rainfall
TRWD Lake Rainfall Totals through October 1, 2026
Lake Level Projections
Note: Lake level projections are based on expected climate conditions, water use demands, and planned operations, including releases and pumping. Actual lake levels may vary based on observed weather, actual water use, and operational responses to changing conditions.
Last Month’s Projection | Historical Lake Levels
Last Month’s Projections | Historical Lake Levels
Last Month’s Projection | Historical Lake Levels
Last Month’s Projection | Historical Lake Levels
Disclaimer: These projections are based on typical operating conditions and expected weather patterns. Actual water use and weather can vary, so observed lake levels may occasionally be slightly higher or lower than the projected range.
Acknowledgments:
- Weather and Climate Insights: Special thanks to Vini de Oliveira and Craig Ottman.
- Reservoir Projections: A big thank you to Vini de Oliveira for his timely reservoir projections.
- Rainfall Analysis: Appreciation goes to Ashley Lowrie for her thorough analysis of observed rainfall.
- Editorial Review: Thank you to Olivia Whittaker for her thoughtful review and contributions to the post.
