**El Niño-driven rainfall shortfalls are the dominant factor shaping sentiment in Panama Canal closure markets.** Watershed precipitation from May through August 2026 ran 34% below the historical average, prompting the Panama Canal Authority to cut daily transits from 36 to 32–34 and impose draft limits on Neopanamax vessels, currently holding at 14.63 meters after planned reductions were deferred. Gatún Lake levels have stabilized near 84 feet—roughly a foot below the five-year average—supported by recent September rainfall gains, yet the Authority projects further constraints if the intensifying Super El Niño persists into the 2027 dry season. These measures raise transit costs, extend wait times for unbooked vessels, and incentivize route diversions, directly influencing implied probabilities around operational thresholds. Key near-term catalysts include October–November precipitation data and the Authority’s next advisory on slot allocations.