St Swithin's Day, if it does rain
Full forty days, it will remain
St Swithin's Day, if it be fair
For forty day, t'will rain no more
Happy St Swithin's Day to you all!
It's very geographically ambiguous that verse, isn't it? I'm guessing it'll be raining *somewhere* on St Swithin's Day, and will probably be raining at least *somewhere* for each of the next 40 days too