I grew my garlic and shallots in the garden last year, and they sat in water all winter long! Disaster!! However, lost 50% of the shallots, but the garlic didn't seem any the worse for their swim, but I agree with Tim, I would probably wait a couple of days, there is no immediate rush to get them in the ground. Check out the forecast - we have a wonderful sunny day today in Essex, if it lasts a few days, then the ground would be ideal. ;D