Traveling first week of April 2019 to Croatia, etc.

Which part of Croatia? Zagreb? Istria? Dalmatian Coast?

Yes, you are probably taking a chance with the weather, but you always do. It's an odds game. I've had great weather in April and May in Europe and rain numerous times, when weather is supposed to be better on average.

Actually, according to Wikipedia, the average rainfall in April isn't much higher than in September:

https://en.wikipedia.org/wiki/Dubrovnik

On the upside, going in April you'll get smaller crowds (or no crowds at all in some places) and cheaper accommodations most likely.

Thanks for such a quick reply. I have the first week of April off from schools. I was trying to find an area for me and my wife to visit that we have not traveled. We have only visited Dubrovnik. So I am looking for some ideas. I would fly in from London to some airport based upon a plan ( have not yet developed).
Thanks

If you've been to Dubrovnik, I'd probably look north. With six days (five nights?), you could do a couple of nights in Zagreb, a couple of nights in Istria, and stop at Plitvice Lakes National Park in between. Istria would make sense if you could find a flight between London and say Pula. London to or from Zagreb should be easy.

Have you been to Slovenia? It's one of my favorite countries. I love Croatia, too, but most of the places I have enjoyed have been on the coast in Croatia, and I'm not sure I'd want to be there in the rain. If you like cities, Zagreb is definitely worth a visit, though it personally wasn't a favorite.

Andrew,
I will be back in touch soon.