In reply to EddP:
There’s a heatwave at the moment, freezing point between 4300 - 4900m, increased danger of rock and ice fall. Nobody can predict what the coming weeks will bring though. Best to just ring the guides’ office (Bergführerbüro) in maybe Zermatt or Grindelwald and ask for the latest local information.
PS there were heavy snowfalls there last week; no idea if it’s all still up there or not.
Post edited at 15:15