The weather in Iceland is highly variable, its location mean that it is open for all the cold water and air streaming down from the polar area. But the Golf stream bring up the warm air and this meet just north of Iceland. That make the moisture that is often in Iceland and more at the south coast. But this as well as Icelandic mountains, make the weather in Iceland unpredictable. In Iceland is a saying "If you do not like the weather, wait 5 min and you might like it then" Meaning that the weather change so often.
The location of Iceland and its name should be enough to scare off most people from coming here, but in actual fact the climate isnt so bad; the Golf Stream bring north the warm ocean all away from Florida just to keep us warm up here. That makes the winter milder and the summers warm. But Iceland is an island, you can expect to see all kinds of weather in just one day, cloudy rainy morning can suddenly change into nice sunny midday, windy afternoon, while the evening can be still with clear blue sky and midnight sun! Because of where Iceland is at 65-67°N, the angle of the sun towards Earth is different then in central Europe. That brings us these bright summer nights, when we can read book outside at midnight without any light, while we watch the sun float on the ocean surface!