Hi Michael,
I have been enjoying your adventure posts immensely; keep up the great work!
I lead hikes for the local chapter of the Sierra Club in Tucson, and in mid-August we’ll be doing a 7-day backpacking adventure in the High Sierra. We’ll be accessing the John Muir Trail, with elevations ranging from 9,000 to 12,000 feet. How cold can it get at this time of year and what clothes/protection would you recommend? Would a light windbreaker over a fleece with gloves and hat be sufficient? Or would you recommend a down jacket, etc.?
I’d appreciate your feedback! Thanks and regards,
Mitch
Tucson, AZ
Hi Mitch,
Thanks for following The Big Outside, glad you enjoy it.
My JMT thru-hike was in late August, so we saw the conditions you will probably encounter. I would expect low temps from the mid-30s to mid-40s, and possibly dipping below freezing. Evenings tend to be milder and early mornings the coldest time of day, until the sun hits your campsite (which isn’t early when you’re surrounded by big mountains).
I carried a lightweight down jacket that was under a pound, and I prefer that over a fleece jacket because the puffy jacket is lighter and more compact, and I don’t need it to be breathable because I’d never wear it on the trail in summer. How warm a puffy jacket you need varies between individuals, of course. But I’d say that, for the time of year you’re going, people who get cold easily would like a down jacket that weighs around one pound or slightly more, while people who don’t get cold easily will probably be fine with a down jacket in the 10- to 12-ounce range. Weight is a pretty good indicator of warmth in a down jacket, although down quality is also a factor. You may want to check out my down jacket reviews.
A great weight-saving option that I recently reviewed is the Sierra Designs Mobile Mummy 800 sleeping bag, which converts to a long down jacket, letting you eliminate the weight and bulk of a down jacket.
When we started hiking in cool, early-morning temps, I just wore my light rain shell until I warmed up, which usually didn’t take very long. But a lightweight fleece vest is a good option if you’re hiking in early morning, and its added insulation allows you to supplement it with a lighter down jacket than you’d otherwise need in camp if you didn’t have the vest.
I also carried a warm wool hat and light gloves for hiking or being in camp on chilly early mornings.
By the way, as you may know, the High Sierra sun can be brutal, especially in the afternoons. I find a wide-brim hat is a must, and I actually prefer taking a good, shady break by a lake for a swim in the afternoon and hiking a bit more in early evening.
I think mid-August to mid-September is the best time of year in the High Sierra: fewer people and mosquitoes (the latter can be very thick, especially near any standing water when there’s no wind) and pleasant temps.
Have a great trip. Let me know how it goes for you. Thanks for writing.
Best,
Michael
Hi Michael,
Thanks for the excellent information! I’ll check out your reviews of down jackets and the Sierra Designs Mummy sleeping bag.
Happy trails!
Mitch
In Ask Me, I share and respond to a reader question. Got a question about hiking, backpacking, gear, or any topic or trip I write about at The Big Outside? Send it to me at mlanza@thebigoutside.com, message me at facebook.com/TheBigOutside, or tweet it to @MichaelALanza. I will answer the ones I can in a post, using only your first name and city, with your permission. I receive a high volume of questions, so I cannot always respond quickly.
—Michael Lanza
Hello Michael,
Thanks for sharing this info! I tend to be a minimalist in terms of trail clothes (and in terms of many other things) so this post brought a couple more questions to mind. For the High Sierras in mid-August…
> In the evening, is it chilly enough that you advise an alternate base layer (to switch with a sweaty base layer)?
> Do you think most people would want an extra lower-body layer (Merino or capilene leggings) for around camp?
> So you would carry a rain shell, but not rain pants?
> Btw, how cold is that water you’re swimming in? Really, I’m curious! You mean a quick dip, or…?
Thank you.
Loving “The Big Outside”
Laura~~
Hi Laura, glad you love The Big Outside! All good questions. I carry minimalist clothing, too, usually one synthetic T-shirt and one long-sleeve, midweight top. I tend to only wear the long-sleeve if I hit the trail early and it’s cool, and switch to the T-shirt once I start warming up; so I avoid getting the warmer top all sweaty and I can use it as a warm layer in the evening in camp (and wear it sleeping if needed). When I arrive in camp in a sweaty T-shirt, I wear it while setting up camp, with a rain jacket over it if I need a little warmth or wind protection, so that my body heat dries out the T. I’ll also sometimes wear the slightly damp T over my long-sleeve in the evening to dry it for the morning’s hike. That’s how I typically avoid carrying more than one of each.
People who need more than just pants in temps in the 40s and 30s may want an extra lower-body layer in camp. I don’t get cold too easily, so I don’t carry that extra layer in summer.
The High Sierra isn’t a very rainy place in summer. I may eat those words someday, but yes, I carry a lightweight rain jacket but not rain pants, which I find too warm to hike in, anyway. However, I like low gaiters with lightweight pants to keep my boots and socks dry in rain, snow, and mud, and I recently reviewed lightweight, zip-off, soft-shell pants that don’t make me overheat, repel light rain, and dry fast: https://thebigoutside.com/gear-review-outdoor-research-ferrosi-convertible-pants/.
Mountain lakes vary quite a bit in how cold they are, depending on depth near shore (deep water doesn’t warm up much, but shallow water can be very comfortable by August), elevation, and whether it’s being fed by a nearby snowfield. So it could be frigid and only tolerable for a quick dip, or warm enough for a longer swim.
Hey Mitch, I hope you are aware that basically from Bishop north past Yosemite is totally smoked out because of 2 wildfires. These fires have altered my up coming plans in the Sierras but fortunately it’s a big place and can options are plentiful.
Thanks for posting MIchael! we’ll keep in touch.
Good luck, Mitch.