How is the weather in Muerren during the end of August? Thanks in advance!
No one can know for certain, but I can tell you that in three trips (one over American Labor Day weekend, one in late September, and one in mid-October) we had more sun than rain every time, when we had rain it was light, but on actual Labor Day we had snow! August should be a good time to go, but mountain weather is fickle, so bring a jacket and a warm layer.
Layers...the weather in Switzerland is very changeable no matter what time of year!