Some information sources for conditions in the Chamonix region:
The Chamoniarde/Office de Haute Montagne (same organization, two names) website
http://www.chamoniarde.com/?page_id=1863&lang=en puts out regular mountain condition reports, (as infrequent as 2 weeks out of season and up to every 2 days in season). The reports are initially in French, with an English translation hopefully online within 24hrs later. The same reports (Fr,En), can be seen on the Chamonix Tourist Office app (Chamonix Lumiplan) and on the Alpine Club site
http://www.alpine-club.org.uk/ac2/news/chamonix-condtions
Another excellent resource is the newly re-vamped Camptocamp site (V6 since last week).
https://www.camptocamp.org To avoid information overload, login, (free) choose the language interface, then under preferences select your activities and choose the areas of interest. For Chamonix, I would recommend, Mont Blanc, Aravis, Aiguilles Rouges, Aosta Valley and Valais W.
The MountaiNow app is also now available since a couple of weeks