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Newbie - Weather and Gen Questions at Altitude

Posted: Wed Jul 11, 2007 8:03 am
by Jstrick5
I have a few questions I was hoping someone might be able to help me out with...

I'm a fairly experienced backpacker but will be making my first trip to Yosemite the first week in August. We'll be hiking the Chiquito Pass Loop and be between 8,500' and 11,500' for the duration of the trip. These are the following topics i'm interested in getting advice about:

1) Weather at altitude - what should I expect as far as temp over the course of the day, thunderstorms, rain, etc. I need to determine what type and amount of clothing i'm going to need to bring as well as outerwear. Everything I've come across up to this point has been general weather information for the Valley not at higher altitude.

2) Insects - How bad can the mosquito's get at this type of elevation?

Keep in mind my trip takes place the beginning of August.

I'd really appreciate advice/experience anyone can provide! Thanks!

Posted: Thu Jul 12, 2007 3:54 am
by Rosabella
You'll want to come prepared for weather. Last summer I was on the JMT for about three weeks (first part of August), and had beautiful weather the whole time.... blue skies, not too hot in the day, not too cool in the evening. :D It was perfect!! Two years before that (same time in August) there was rain every afternoon for two weeks with some pretty scarey thunderstorms thrown in just to make it more interesting! :\

Unfortunately, there's no crystal ball, so just plan on layering. Some type of raingear is a must. Even with a good weather prediction, I wouldn't trust it for a week.... weather can change. As far as other clothes - I normally bring shorts, long polar-fleece pants, cool top, lightweight polar-fleece jacket, windbreaker jacket, and hat. I do bring fleece gloves and hat because it can get cold in the morning. I bring two pairs of socks and underwear... but other than these last two items I don't bring any extras. I bring my bathing suit for swimming and to wear while I do laundry. I tend to get cold easily, but layering always works for me.

The mosquito situation is kinda the same thing... varies from year to year, but this was a pretty mild winter so hopefully the mosquitos won't be out in full force. Check with the "Sticky: Mosquito Report 2007" at the top of this section of the Index for current reports and updates.

Have a wonderful time on your trip!!

Posted: Fri Jul 13, 2007 4:41 pm
by Haiwee
As for weather: prepare for everything! I've been snowed on in the Sierra backcountry in July and August more times than I can remember.

Posted: Mon Jul 16, 2007 2:50 pm
by SPeacock
Daytime temps can be very hot (sunglasses/UV protection/wide brim hat with strap to keep it in place). I'd suggest light weight long pants and long sleeve shirt mainly because of sun. But most hikers you will see up there will have shorts and T. Keep 200 fleece handy at top of pack for those stops you have to make just to look at the scenery. You will cool quickly. I have been using just Precip rain top not bottom for afternoon showers or for a bit of layering for evening chill. You can get by with a poncho - many do. Usually not so cold in August that you can't continue hiking with wet legs. But if you have the time, put up the tent, and crawl in for an afternoon nap while listening to the rain and thunder.

20F bag will be sufficient. You can expect afternoon T-showers, so a tent/rain fly would be sufficient for it and the bugs at night. Don't forget the sleeping pad. Showers are usually very local and do not last long. Nights are cool so when sun goes down, expect long pants, a couple of layers topped off with a hooded parka. You can toss a down vest in the bottom corner of your pack if you are paranoid. You will probably spend most of the night on top of your bag, and sweltering in daytime high temps.

August, at 10,000, 20's F at night are not uncommon. You may be surprised to see frost in the morning close to creek bottoms.

Mosquitoes are kept at bay with DEET, long pants and thick outer hiking socks and long sleeve shirt. Hooded parka/rain top is best. They are just a minor nuisance. Camp away from water and in a breeze and you may never seen them. Only really active in late afternoon and early morn.

Posted: Fri Jul 20, 2007 4:51 pm
by Jstrick5
Great advice, really appreciate everyone's help!

Posted: Mon Jul 23, 2007 7:10 pm
by Phil R
Always be prepared for cold, rain, hail, and bugs in the Sierras. I've been in some knarly hailstorms in August!