we don't often get 'heavy rains' here. but yes sometimes, if it rains, it then pours down properly - I love that.
basically, the dryest period is from mid may until end of august. during that time it normally hardly rains at all. but as various people have expected, there's often those one or two days in august when we get a proper midsummer storm. after that it clears up again.
then there's a weather phenomenon locally called 'la gota fría' (the cold drop) which marks the end of the proper summer period. those are always a few rainy days in a row with quite a lot of heavy rain too and this can happen anytime between end of august and mid oct. in the last two years it happened in september (2013 end of aug/start of sep, 2014 mid sep). after that it clears up again, but it normally then doesn't get as hot anymore as before. so for people coming in september or october, you always have the risk to hit those days. but lately october was always amazing while september had those rainy days. I remember one october (2007) when it rained for two weeks straight, but that's totally out of the ordinary.
then the winter is actually not very wet. It's humid - very much so - but it doesn't rain too often. another period when we do get a bit more rain is just before the season starts again - march and april. again you can be super lucky and already get proper beach days (at least in april), but you can get a few rainy days too.
