Is it a Good Time to take a Tour in April ?

What do you mean by a nice time? Weather.com says the daily temperatures are mid-40's daytime and mid 30's at night. Mix of wet and cold and dry and cold. But probably fewer tourists!

Read through the pages here and you will get an idea of what to expect. April is still winter there. We were there again this past week and it was full on winter! One day our snowmobiling excursion was closed due to extreme weather, to give you an idea. As long as you have layers, you will be fine. And a good attitude:) Some people are miserable with the cold/wind, but others like us don't mind it. Proper clothing makes a world of difference.

I don't think there is a bad time to visit Iceland. We have been most months of the year. As for do's and don'ts, what are you referring to? What drew you to Iceland? I would need much more information to make any real suggestions.

Get a guidebook. Read through the many posts here and on TripAdvisor Iceland forum. Decide what you'd like to see and how long you want to stay there. Decide if you want to self drive or take a tour. Put together a draft itinerary and come back here for advice.