Sweating sickness outbreaks followed slightly wet summers: a weak hint that did not strengthen
The old claim is that outbreaks followed prolonged rain. First test (25 October 2026): the two summers before an outbreak were wetter than normal in England (chance 7 percent) and in northern France (6 percent), about 3 percent combined.
Second, fairer test the same day: each of 171 French outbreaks measured at its own department against that place's own climate, with the outbreak pattern slid along the record so clustering cannot fake a signal. The chance stayed at 6 percent, but the effect is tiny: outbreaks followed summers only 0.06 of a typical year-to-year swing wetter than usual. England's five outbreaks: 0.63 of a swing wetter, chance 8 percent; 1517 still contradicts.
Verdict: moved back from 'looking good' to 'not checked yet'. A real but very weak lean toward wet years, or noise. It does not single out any cause.
What to check next
- Seasonal rain records (winter and spring) instead of summer soil wetness, since the chroniclers spoke of wet winters
- Harvest and grain price series for northern France 1718 to 1874 as a second measure of bad wet years