On 27 July 2026, the average daily discharge of the Rhine at Basel-Kleinhüningen was lower than 1 % of all daily values recorded since 2020. The flow ranged from a minimum of 343 m³/s to a maximum of 559 m³/s, with a mean of 463 m³/s. These figures are exceptionally low for the time of year. The maximum discharge on 27 July ranked 25th out of the last 30 days, 7th among all July days since 2020, and within the lowest 3 % of all days in the record.

Over the past 30 days, the highest flow was 1068 m³/s on 2 July 2026, while the lowest was 359 m³/s on 25 July 2026. Table 2 lists the months with the lowest flow conditions since 2020; July 2026 already appears as the second-lowest on record, with a minimum average flow of 456 m³/s, only slightly above the record low of 436 m³/s set in August 2022.

Low water levels on the Rhine have consequences that reach well beyond the river itself. Cargo vessels have to reduce their load to stay clear of the riverbed, so more trips are needed to move the same volume and transport costs rise sharply, with the effect passed on to industries that depend on the waterway for coal, oil products, chemicals and grain. The shallower water also heats up faster in summer. Warmer water encourages bacterial growth, which can produce noticeable odors, and it holds less dissolved oxygen. The combination of higher temperatures, lower oxygen and more concentrated pollutants degrades water quality and can lead to fish kills. Swimming is generally discouraged under these conditions because of the higher bacterial load. Further effects include restrictions on power plants and industrial sites that draw river water for cooling, since they may no longer discharge warmed water without exceeding temperature limits, reduced dilution of treated wastewater, pressure on water supply and irrigation in the surrounding area, and falling groundwater levels along the river that affect riparian vegetation and wells.