St Swithun; hypothesis testing in Winchester

We visited the shrine of St Swithun in Winchester Cathedral. I do like the hypothesis testing element of the St Swithun story. St Swithun's day is July 15th and that was hot in most parts of the country. But it has rained since! However if you read https://en.wikipedia.org/wiki/Swithun you'll see some attempt at scientific reasoning behind the saying based on the position of the jetstream over the UK in mid-July. I do wonder how geographically focused the original saying could have been. Surely no one could have thought it would apply to Wigton, or Australia?? But given the weather in Winchester this year, it hasn't even worked in Swithun's town.