Yes, Andrew is right. A shower is when it rains for a short period of time. "I just got caught in the shower on my way home!" (This is true by the way, my feet are soaking wet.) "There will be strong winds and showers all over the country." - Taken from English weather forecast.

I think that it is a heavy rain that does not last for long, anyway without the possibility of having hot water, only cold water is usually available.