There’s nothing more aggravating than getting out of bed and discovering that it’s raining. Attempting to figure out how you’re going to get to work might be anxiety-inducing, mainly if you rely on public transportation. Your employer may be excellent and forgiving at one moment, but you have to hope the bad weather dissipates the next.
This kind of reaction from your employer appears to be out of line. It is evident that you should not put yourself in danger if the weather is genuinely awful outside, forcing you to swim. It makes us believe that perhaps the employee is attempting to pull a fast one on their employer by making it appear as though the weather was worse outside.