I don't see that Groundhog day is any worse than the other days associated with weather:

St Swithin's Day - 15th July
St Swithin's day, if thou dost rain,
For forty days it will remain;
St Swithin's day, if thou be fair,
For forty days will rain nae mair.

Sts. Gervasius and Protasius - 8th June
Apparently there is a similar legend attached to this saints day in France, perhaps Bel knows if it celebrated in Quebec?