Clue from nature AD 1718

Tree-ring summer wetness for northern France, 1716 to 1874

Old World Drought Atlas, 39 grid squares over Picardy, Normandy, Ile-de-France and Flanders. Outbreak years compared with all other years, with the outbreak pattern slid along the record 10,000 times to keep its clustering: the year before an outbreak was wetter by 0.46 index points (chance 7 percent), two years before by 0.32 (15 percent), the outbreak summer itself no different (39 percent).

How it connects

This clue from nature supports this hunch Sweating sickness outbreaks followed slightly wet summers: a weak hint that did not strengthen chance about 6 percent

This clue from nature is a clue for English sweating sickness: what was it?

This clue from nature we read it in Cook et al. 2015, Old World Drought Atlas: tree-ring summer scPDSI on a 0.5 degree grid, AD 0 to 2012, NOAA study 19419