Rhine water quality is continuously monitored at the Rheinüberwachungsstation Weil am Rhein (RÜS). This monthly insight focuses on the temperature parameter in August 2026.

In August 2026, the Rhine water temperature at Weil am Rhein averaged 24.6 degrees Celsius. The lowest recorded temperature was 22.2 degrees on August 24, and the highest was 26.1 degrees on August 6. The month began with a temperature of 25.3 degrees on August 1 and ended slightly cooler at 23.7 degrees on August 31. The coldest daily average therefore occurred on August 24, while the warmest daily average was measured on August 6.

Looking at the long-term record for August since 2002, the warmest August was 2018 with a mean temperature of 24.7 degrees, and the coolest was 2014 with a mean of 19.0 degrees. August 2026, with a mean of 24.6 degrees, ranks just below the record and is clearly a very warm month compared to the historical range. The final day of the month still measured 23.7 degrees, which is well above the threshold for comfortable swimming. For anyone planning to enter the river, the water is inviting, but always remain cautious about currents and local conditions. Before heading out, check the official guidance on Schwimmen im Rhein or install the BachApp for real-time safety information. 🏊