What do I need to consider when rock climbing at night?

Question

One of my dream climbs is to climb Snake Dike on Half Dome at night with a full moon.

Are there any special considerations for rock climbing at night beyond bringing headlamps and extra batteries and dressing warmer than normal?

Answer 1

General advice for climbing at night:

• Don't do it if you are new to climbing.
• Avoid it, even if you are not new to climbing.
• Be prepared for it on long routes, even when you are not expecting to be climbing at night. Most of my night-climbing came about unplanned.
• Make sure you can do everything involved in climbing with your eyes closed. In the shower. (Setting up for rappel, tying in and untying, building rappel anchors... just to name a few things...)
• Pay extra attention to communication with your partner.
• If clouds begin to cover the moon, conserve batteries and turn off your headlamp when belaying.
• Make sure your skill level is such that the idea of turning your lights off at a belay or loosing your light altogether doesn't frighten you.
• Even if all is going fine, keep your eyes out for places you might be able to spend the night if things go south later on. Don't dismiss small ledges, I have spent a night sitting upright. That was way better than sleeping at a hanging belay.
• Know how long your headlamp lasts and bring extra batteries.
• Make sure someone knows what you are up to and let people know when to expect you back. This one is not just for your safety. If someone tries to find you at night and you are not in your tent, they might assume something has happened and contact YOSAR.
• Figure out how to attach your headlamp to your helmet. Before you start climbing.
• Plan in extra time. It will take longer.
• Be extra diligent about researching weather conditions, since you won't be able to see weather approaching as well.
• Move efficiently but safely. Your belayer will thank you, since it can get cold.
• Don't rely on technology to find your way. (Applicable to life in general)
• Climb with someone you have climbed with before. This goes back to the communication issue.
• Get some sleep before you jump into your car and drive home.
• Have the "cuddle talk" with your partner. Don't engage in any night-climbing with a haphephobiac who would rather die of hypothermia than share some body-heat.

Here is some advice for climbing Half Dome at night:

• Harness up for the decent on the cables. That section of the dome can have whet spots, and since you are at significantly higher elevation than the valley floor, you might encounter conditions where parts of the decent are frozen over. Temperatures can be more than 20 degrees F lower up there, which can mean below freezing, even in summer months.
• If you are planning on descending the death-slabs, make sure you have taken them at least once during the day (either up or down). Route-finding for those unfamiliar with that decent can become a nightmare at night.
• Get an overnight-wilderness permit for Little Yosemite from the ranger station near the post office in the Valley. That way, if you don't make it back and have to sleep somewhere on you way back down you won't get ticketed.
• Since you are already at the ranger station, ask for the conditions up there at night.
• There is a section where the dike splits off in two directions. Make sure you stay on route.
• Don't sleep on top. It is illegal even with an overnight permit for Little Yosemite.
• Don't walk off the edge above the northwest face.

Answer 2

Route finding might be a problem:

• If the approach is not obvious (from what I read about Snake Dike, it isn't), you could waste much time blundering there, looking for cairns and what not.
• You could miss an important belay point on the route.
• You could wander off to another (harder) route in the middle; it happens to me all the time during the day, so I figure it's all the more a possibility at night.

Take a good map and possibly a GPS for backup. Actually, I'd probably never go climbing an unknown route at night (YMMV), but this is much less of a problem if you have already been there.

Also, make sure the weather is going to be good. Any clouds will ruin your full moon. Also (depending on the season) the wall may be icy at night if it was wet during the day!

For unforeseen circumstances (stuck on the wall? Stuck at the summit?), take an emergency blanket, extra food and adequate water.

Finally, make sure everything you do is legal. Authorities don't like nonstandard hours.

Answer 3

Depends on your headlamp. I use a Petzl Ultra Vario headlamp for caving that can cast a beam 200m, so when I've got that on I can see pretty much the same as climbing during the day.

I've climbed at night before, there wasn't any real significant difference. We happened to be climbing during a full moon as well, and as soon as that moon came out it was very bright on that rock face, much brighter than down on the ground in the trees.

One thing we noticed climbing with headlamps, is holds are sometimes easier to find. Your lamp will cast a shadow behind the holds, making them stand out a lot more than during the day when the sun is beaming from above.

One other thing about climbing in the dark is you lose the sense of how high you are off the ground. Your belayer's light gets smaller and smaller, but you don't get the same sensation as you do during the day.

I think the greatest danger climbing at night, is falling rocks. You're not going to be able to see them coming, and if you do see them you aren't going to be able to react fast enough to get out of their way. I remember belaying at night and not knowing there was a rock falling until it hit the ground beside me, so keep your helmets on.