Trip in April

Early April is a lot like the northern US-mild days and chilly nights. If you're from that part of the country or Canada, it will most likely feel like spring. If you're south of the Midwest, it will feel cold. Take layers no matter where you're from.

AGS???? What is that?

That would be Austria,Germany and Switzerland.

April is a transitional month. It can be cool (usually not cold, though), or warm. Either way, the weather is usually damp. And a lot depends on the region and altitude. SW Germany - the upper Rhine valley- is the warmest region of the country, and surprisingly, SE Germany - Upper Bavaria- is the coldest. The Alps will still be covered in a significant snowpack. The high altitude villages of the Berner Oberland will likely be thawing out from the winter... which means, lots of mud, "natural" fertilizer and a lot of infrastructure closures.