How cold of temps will you climb in?

We get so little sun in the winter here in central Michigan, but it makes so much difference.  We've been bouldering all winter so far, lots of 30 degree and overcast days.  I'm just curious how cold everyone can climb in?  We haven't got a full sun day here in about 3 weeks, I figure 20 and sunny would be climbable in our area as the rock shelters a ton of wind and absorbs the sun really quick being a south facing band of rock.

I have climbed in 20F and full sun, and it was very pleasant in the dry desert environment. I have also climbed in 20F and theoretically-sunny   Midwest winter, and it felt a lot colder and a lot less pleasant. The difference was humidity.

I figure that for a local bouldering spot, it is a low-investment high-reward situation. If you hike out and it is too cold, so you give up... You had just spent an hour outside getting some fresh air and exercise— oh, the horror! ;)

All about the sun.  I was going to go out today, but was in the 20s and "milky haze" conditions, so I went to the gym.  If it had been full sun I would have been outside for sure.  

It's all about the sun & wind here. Sunny no wind 20s are perfect for bouldering.

When I was a youngster in college climbing in the Gunks, around 30F - maybe a little lower in full sun/no wind.

Now at 66, I don't really like it below 50F.

Lena chita wrote:

I have climbed in 20F and full sun, and it was very pleasant in the dry desert environment. I have also climbed in 20F and theoretically-sunny   Midwest winter, and it felt a lot colder and a lot less pleasant. The difference was humidity.

I can't think of a reason that higher humidity would make one feel colder.

 On the other hand, if along with the higher humidity the ground was wet or the air scattered more sunlight, then those things would make it feel colder. The dry desert would feel warmer in the sun because the ground heats up faster. Get up off the wet or icy ground and on dry rock to feel warmer.

27F no wind, 30F yesterday in south NH with lots of wind. still crushed it

Oh, Jon, I've lived in S.F. & 40 on a foggy day is WAY colder than 20 in Bishop on a sunny day.   

But you are right. It is different. get up & go!

Thre Granite down here climbs best in the 20s - 50s if the sun is on it.

Jon Nelson wrote:

I can't think of a reason that higher humidity would make one feel colder.

I'm not sure of the answer, but I have a couple of guesses:

1. increased temperature-holding capacity of water compared to air. May essentially act as an insulator working to keep things cold.

2. Dry air, with fewer molecules/particles per cubic area may not be able to conduct temperature as well as humid air due to the decreased surface area of those particles (I'm guessing that weak electromagnetic forces form microscopic droplets of water, ie humidity isn't molecular H20).

3. Indirectly, the clothes you wear when it's wetter out may trap more moisture making you colder.

Re: OP, Climbing in February in RRG we woke up to 1/2 inch of sleet plastered to our tent. We proceeded as planned, climbing in 25F, windy, overcast and snowy conditions. It was pretty unbearable until the sun came out and the storm passed. Like others here, for me, 20 deg in a sunny location is no problem, I'd probably want >freezing for the shade, and it's gotta be dry.

I suggest you get some pons and tools and get up to da UP!

Jon Nelson wrote:

I can't think of a reason that higher humidity would make one feel colder.

 On the other hand, if along with the higher humidity the ground was wet or the air scattered more sunlight, then those things would make it feel colder. The dry desert would feel warmer in the sun because the ground heats up faster. Get up off the wet or icy ground and on dry rock to feel warmer.

I might be misunderstanding the topic of interest, but I believe that damp air “feels” colder because of the high specific heat capacity and low thermal conductivity of water.

i.e. the more damp the cold air, the more energy you need to put into it in order to warm it up.

Basically, a wet cold blanket is much less fun than a dry cold blanket.

https://decodedscience.org/why-does-damp-cool-weather-make-it-feel-colder/

Been getting out in 0C to 15C lately for sunny sport climbs, lately.

5C with a light breeze and sustained full sun is perfect.

Below 15C it starts to get unpleasant if theres  wind/gusts and/or clouds/overcast. 

Above 15C and the rock starts to feel less than ideal for tenuous moves, but way more fun for slamming hand jams.... until they start greasing out at around 25C.

Circulation seems to be a big part of it, person to person. I have friends all over the age range that complain of weak circulation in their hands and face, and rely on hot hands packets and balaclavas&goggles when its south of 10C. I’ve also noticed I’m MUCH less tolerant of the cold when dehydrated, for whatever reason - go figure.

edit: haha Detrick.... great minds! And oh man, waking up to an iced over tent at the RRG is how you know you’re living the good life.

There are definitely those days that are just "damp" and the cold seems to cut right through you opposed to some other overcast days.  The ground just froze here in he last week, nice to have everything froze honestly and leave the tarp in the trunk.

I put it up in another thread, but we use a "warm bag".  This consists of 2 nalgenes that were filled with boiling water, wrapped in a towel and placed in an old down coat wrapped by an old gore tex coat.  Put the shoes in there, gloves, extra socks or whatever and it stays super warm.  Found that going for a 5 minute walk will really warm the toes up as well, of course I put on my wool socks that came out of the bag first.  Hands usually stay warm, its the toes damnit.

Its awesome to hear of others climbing in the frigid, it aint all bad.

I'll climb well below freezing outside for bouldering, sun or not. I'll start calling it for route climbing if I can't feel my fingers after a few moves usually if it is <40 degrees F and no sun, with sun it can probably go to ~30 degrees. 

Sport climbing maybe 45-50. Any colder and your fingers go numb by the second bolt. Bouldering can perform in much colder temps maybe down to 25 or so.

Detrick S wrote:

I'm not sure of the answer, but I have a couple of guesses:

1. increased temperature-holding capacity of water compared to air. May essentially act as an insulator working to keep things cold.

2. Dry air, with fewer molecules/particles per cubic area may not be able to conduct temperature as well as humid air due to the decreased surface area of those particles (I'm guessing that weak electromagnetic forces form microscopic droplets of water, ie humidity isn't molecular H20).

3. Indirectly, the clothes you wear when it's wetter out may trap more moisture making you colder.

Re: OP, Climbing in February in RRG we woke up to 1/2 inch of sleet plastered to our tent. We proceeded as planned, climbing in 25F, windy, overcast and snowy conditions. It was pretty unbearable until the sun came out and the storm passed. Like others here, for me, 20 deg in a sunny location is no problem, I'd probably want >freezing for the shade, and it's gotta be dry.

I suggest you get some pons and tools and get up to da UP!

Folks often confuse humidity with wetness as Detrick and Brent seem to be doing. Humidity is a measure of the water vapor content of the air, not the wetness. The properties of humid air are practically identical to dry air at the same pressure, and where it differs, tends to be in a direction to actually make one feel warmer (such as a lower thermal conductivity and reducing our skin's net evaporation rate). People feel colder on "moist days" not because of the humidity, but generally because there is less intense solar radiation and the ground is colder. As I said, I can't think of a reason Lena Chita would attribute coldness directly to the humidity. Yet it seems to be a common misconception.

Just a little bit of high clouds might not seem to be affecting the amount of sunlight, yet the amount of cooling is significant. I recall during the last partial solar eclipse, the moon blocked out half the sun, yet the brightness of the surroundings was hardly any different. It is easy to be deceived by the influence of a slight cloudiness on temps. 

Psych power overcomes coldness better than anything. Grey skies may "dampen" the psych and make one cold more than the physical influences. Just a theory though-

Bouldering, maybe down to 25ish or 30, no wind, sunny. A handwarmer in the big pocket on the front of a pullover hoody, plus, side zip snow boots I can just pop in and out of in bare feet. Keep your climbing shoes warm, throw them inside your jacket, next to you, like ice climbers and their gloves . Oh, and throw them on the dash on the drive out. Putting on cold shoes from a cold pack from a cold trunk on the drive out...less than fun.

Someone mentioned dehydration and feeling colder. Also if you are short of calories and/or short on sleep, you'll get cold faster. And? I don't know if we acclimate, or just what? But 40 and sunny even with some snow around? Mid  February? Break out the tank top! Mid September? Brrrrrr!

I have also raided my ice climbing stuff and brought my belay puffy bouldering. Goretex pants to slide on over whatever I'm climbing in, if the hike in will be through wet or frosty stuff. 

A thermos with something warm to drink....

Geez. 

Just do what you'd do for ice climbing, except in somewhat warmer temps, and the opportunity to play on rock. Minus the pokey bits.

On the other hand, ice? Well. This old girl does enjoy the berserker appeal of very sharp pointy things on all appendages. 

The coldest I've ever been, wasn't the super frigid subarctic temps that show up now and then here...

It was in August, arriving at basecamp for Mount Borah, 7500' elevation. But, arriving in the middle of the night, actually the wee hours of the morning. Trying to lay down and sleep, with not enough to get warm? I was shivering violently soon enough. My teeth were chattering so hard I was worried I'd take a chunk out of my tongue.

Very tired from a long drive, arriving in the dark, at a time when bodies shut down, hungry, dehydrated, a fair bit of elevation gain, a weather change to colder than expected....and not prepared for being cold. Cuz...August, eh? It didn't happen, but throw in a creek dunking, or getting soaked in a downpour? Cold suddenly gets serious.

Jon Nelson wrote:

Folks often confuse humidity with wetness as Detrick and Brent seem to be doing. Humidity is a measure of the water vapor content of the air, not the wetness. 

D’oh!

I’m still confused as to how “water vapor content of the air” is different than “wetness” of the air, but maybe I’m missing something. Looks like I’ve got some homework to do! 

Thanks Jon!

Edit: Now I am just confused. I’m pretty sure everything I said before was valid and reasonable. Not sure I agree that “cold damp air” and “cold dry air” have the same properties, but that might be more of a semantic/ill-poised problem dynamic rather than a true disagreement?

But I guess the volume of water in the air between dry and humid air isn’t that drastic, which puts a slight damper on my whole “watery air leads to more chilly conductive-esque cooling than purely air on skin convection-esque cooling” theory.

I’ll definitelty buy in (for $1) that it most often has more to do with the weather comditions resulting in damp conditions that make the cold feel cold, rather than the damp air itself.

And I’ll defer to the expertise of veteran Seattle climbers when it come to humidity. If anyone understands the nuances of damp conditions....

Mostly I just feel confused, now.

If anyone needs me I’ll be wrapping myself in cotton and heading out to play in the snow, like the genius I am...

Jon, If you had ever jetted carburetors you would not have said that about humidity. 

We jet differently depending on humidity. 

Dry air and humid air are different. 

One is dry the other is moist! 

You sir are wrong!

glclimber 21 wrote:

I put it up in another thread, but we use a "warm bag".  This consists of 2 nalgenes that were filled with boiling water, wrapped in a towel and placed in an old down coat wrapped by an old gore tex coat.  Put the shoes in there, gloves, extra socks or whatever and it stays super warm.  

THIS IS BRILLIANT.

Jon Nelson wrote:

I can't think of a reason that higher humidity would make one feel colder.

 On the other hand, if along with the higher humidity the ground was wet or the air scattered more sunlight, then those things would make it feel colder. The dry desert would feel warmer in the sun because the ground heats up faster. Get up off the wet or icy ground and on dry rock to feel warmer.

I admit that humidity and wet ground go hand-in-hand in my experience of cold-weather climbing.

Subjectively, a cloudy 35F day in NYC winter feels way colder than a cloudy 35F day in Las Vegas to me. I have attributed that to humidity in the past, but I don’t have anything other than internet search to “prove” it.
:)

Internet research in support of my feelings.

It's the humidity, The east coast on average has higher humidity than the west coast & you need to jet Carburetors differently even though you are at the same altitude.

It's a learning curve that you learn fast if you what to keep getting a paycheck. 

For those of you that don't know what jetting is. Gas burns best at about 13.5 parts air/1 part gas. to get that a Carburetor has three sets of jets that need to be changed at different altitudes or if there is a lot of water ( humidity ) in the air. 

Modern Fuel Injection does the same thing just differently.