UKC

what conditions would you look for to climb mountaineering routes like the ridges on ben nevis?

I can get the principle of gullies needing the build up of consolidated snow and refreeze cycles, but its not clear to me what ideal conditions are for ridges which could be done in summer as rock climbs.

would ideal conditions be a certain amount of snow?

is temperature going to affect it if things are abit melty?

in the interests of learning and the proviso of no stupid questions, I'd be keen to hear any opinions

Its doable in pretty much any conditions.

Doable in more or less any conditions, but much more enjoyable in some.

The worst part about doing these sorts of routes in in-between conditions is that at some point you're going to have to decide it is the right time to put your crampons on and get the axe out, and it will always be either too soon or too late. 

As others have said, they can be climbed in any conditions, though verglass and deep powder will make them a lot harder.

I think the biggest concern however will be can you get onto the route and off it safely. All the ridges on Ben Nevis have approaches which can be exposed to avalanches at some point for example.

more enjoyable with some neve and ice on the ridge although bullet hard and very icey maybe not as pleasent as a gully / ice route. Snowed up rock with little other build up beneath can be very slow going and seem hard for the grade on a ridge but can often be the only routes really 'in' or (fairly) 'safe' during such conditions, if there is frozen turf beneath the powder its a different story. Conversely if there is a huge amount of build up sometimes the gear can be sparce depending how defined the ridge is / the route. i think the very best conditions I enjoyed for these routes up to grade IV are a bit loose to firmish neve on the easy sections with good firm build up beneath (neve/ turf) and neve / ice / frozen turf on the harder bits. Obviously with acceptable avalanche conditions for your day. On the popular routes if there is heavy neve build up normally the crucial gear / belays are still there so its just bolder but less scary in a way as the placements are bomber and the ground tends to be more evened out

Ideally you want a good build up of neve underfoot so it’s easy to move with crampons on.  If the rock is dry and ice free it’s easier to protect.

Most of the ridges on the Ben are fairly forgiving and can be climbed in a range of conditions, but powder on dry rock is particularly unpleasant as it requires crampons but doesn’t give purchase. Deep snow will obviously makes things slower and harder. 

Whilst ridges themselves may be relatively safe from avalanche hazard, don’t underestimate the approaches.

Temperature will obviously have a huge effect on any winter route. Soft underfoot is very different to 5c and raining. Only you can decide how much is too melty. Remember the hazards which can occur eg rockfall/cornice collapse and make decisions accordingly. 

I highly recommend buying Chasing the Ephermeral. It's got answers to all these sorts of questions and if I'd had a copy when I started winter climbing I'd have got up a lot more routes!

I climbed Castle Ridge a while back in tough early season conditions - deep powder, no buildup - and found it very slow going (probably harder than either Tower Ridge or North East Buttress, both of which I climbed in very good conditions).

thanks all for the useful replies.

Not to be underestimated. Avalanche risk on approach, and tricky for III when not consolidated. It's one of my most memorable winter climbs but also one of my slowest for the grade and the only winter route where I took a proper lead fall (a small rock edge broke on slabs and so one axe pinged and the other didn't hold in cruddy ice... I started to skid and my crampons clipped an edge causing rotation that led to a full back flip and a fortunate soft landing in snow about 8m down. I was incredibly lucky and my belayer hadn't realised it had happened until the direction of expletives indicated I was no longer where I should have been. Subsequently no more drama, and a wonderful crux section, but a top-out in the dark at Easter.