Hi Hettiab
They have a saying in Iceland (and they even print it on t-shirts):
"If you don't like the weather in Iceland, just wait five minutes"
It's absolutely true - you can forget 'four seasons in one day' because you are very likely to get four seasons in the space of an hour!!
Whatever you get, I guarantee that you will have a fantastic time but, don't bother to take a brolly because you will never keep it up as it is always blowing a gale there, and the dry witted locals will look at you as if you are a loony if you even attempt it. On the other hand, if you did manage to get a brolly up, the chances are that you would very swiftly end up in Norway.....
Don't forget your swimming gear but don't worry too much about all the warnings to put plenty of conditioner in your hair before you go into the Blue Lagoon. I slipped on the underwater mud as I waded out and did a spectacular face plant into the lagoon (much to the amusement of our group!). I'll admit that I didn't come up with hair like I'd 'just stepped out of a salon', but it didn't take on the brillo pad quality that we had been warned about either.
Not long for you now - have a super trip
Mandy