I'm planning to go to Zermatt for the last week of September and was thinking of climbing the Matterhorn. Guiding seems to be only until the 15th so I was wondering if my chances to climb in good conditions around the 30th were low?
Also, for people flying in from sea level, what's the normal acclimatisation schedule to climb it?
Can't help you with the timing and we were already acclimatized when we did it but following the general rule of thumb I would recommend trying to spend a night at around 8500 feet before moving up to the Hornli hut which is at about 10,000. Plenty of people go right up to 10 but if you live at sea-level (as I do) you might want to take that extra night at 8. The extra night could make the difference between being able to go up or not and might save you from feeling pretty crappy. I just did two nights around 8 before heading up to 11 and still had a killer headache that night.
Obviously it varies from year to year but we climbed it around that time in '07. The hut at the base of Hornli was officially closed for winter but you can access it (there's basically an unlocked window with a ladder.) It was fairly warm and uncrowded (maybe 5 people on the mountain?)
I would think there´s a reasonable chance that end of Sept would be OK, it depends on the weather really doesn´t it.
It´s high, I´d recomend acclimatisation, it´ll certainly not do any harm. Radson seems to have been sensible. If he did the normal way via the Gouter up Mont Blanc he´d have been nicely acclimatised for the more technical Mat. (just guessing though)