St Swithin's day is 15th July and is traditionally an indicator of weather:
"St Swithin’s Day, if it does rain
Full forty days, it will remain
St Swithin’s Day, if it be fair
For forty days, t'will rain no more."
Hence the weather in the middle verse.
The battle of Agincourt was famously fought on St Crispin's day.
St Swithin's day is 15th July and is traditionally an indicator of weather:
"St Swithin’s Day, if it does rain Full forty days, it will remain St Swithin’s Day, if it be fair For forty days, t'will rain no more." Hence the weather in the middle verse.
The battle of Agincourt was famously fought on St Crispin's day.