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I wore shorts and a T-shirt and carried a sun umbrella for most of the PCT and would do the same again.
 

PCT Weather: Temperatures, Rain & Snow, Mosquitos, and Gear to Handle them

Photo album at bottom!


During my 2009 PCT thru-hike, I carried a small notebook and recorded basic data about each day on the trail: the number of miles walked, high and low temperatures, maximum and minimum elevation, and elevation of campsite, in addition to notes about my experiences of the day. I used a High Gear Summit watch as a thermometer, setting it off to the side each night and carrying it somewhere on my pack during the hottest hours of the day. The coldest part of the night is almost always immediately after dawn, so it's easy to get an accurate reading — just look at the thermometer when you get up.

PCT Temperatures

I think 2009 was a fairly typical year in terms of temperatures, and my data below can be considered representative for preparing for thru-hikes of the PCT in the future. However, if you start before the end of April or finish after mid-September you will likely see more low nighttime temperatures than I did.

Interesting facts about temperatures on the PCT in 2009

  • The coldest night during the first 40 days of my thru-hike was at the ADZPCTKO kick-off at Lake Moreno (0 C / 32 F) on day 2 of the hike. The park is in a deep basin next to a lake.
  • The hottest day (40 C / 104 F) was when crossing Gorgonio Pass between the San Jacinto and San Bernardino ranges.
  • Most warm days (≥ 25 C / 77 F) were in Southern California up to Kennedy Meadows and from Northern California to Central Oregon between Donner Summit and the Three Sisters.
  • Almost all cold nights (≤ 0 C / 32 F) were in the Sierra Nevada. My coldest night (-4 C / 25 F) was also at my highest campsite — June 5, 3430 m (11250 ft.), mile 750 of the PCT next to a mountain lake.
  • Chilly (≤ 5 C / 41 F) nights were experienced in all segments of the trail except during the peak of summer (July 14 — August 7) when I was in the northern half of Northern California and the southern half of Oregon.


graph of temperatures on the Pacific Crest Trail (PCT)

Gear for dealing with heat and cold on the PCT

Important: all clothing for the PCT and for thru-hiking in general should be quick-drying.

  • Your sleeping bag or quilt should be proven to keep you warm down to a couple degrees below freezing. It's probably not worth the effort to a lighter sleeping bag or quilt mailed to you after the High Sierra, but if you choose to do so, it should be proven to keep you warm to about 2 C (36 F).
  • A wind shirt, wind pants, shorts, and a short-sleeved shirt are appropriate for all sections of the PCT.
    My favorites:
    - C.A.M.P. anorak (there are many similar products by other manufacturers)
    - wind pants made of slightly heavier material (they receive more abrasion and abuse than windshirts
    - mid-length no-name polyester shorts with front pockets
    - Icebreaker superfine 150 short-sleeved shirt (superb for comfort and avoiding smells)
  • A long-sleeved lightly insulating shirt is appropriate for all sections but may be superfluous for Northern California and Southern Oregon between July 14 and August 7 (the peak of summer).
    My favorite:
    - Marmot Cocona PowerDry shirt
  • A lightly insulated thermal pant is much needed for April through June and mid-August through September.
    My favorite:
    - Marmot Cocona PowerDry thermal pant
  • An insulated jacket or sweater of some kind is nice to have for April through late June and late August on, though it can be avoided without much discomfort (unless you get cold easily) by getting in bed quickly and getting going quickly in the mornings. A ultralight down jacket from Montbell is a good option.
  • A sturdy reflective umbrella is very much needed throughout the PCT, mostly for sun and heat protection, but also for rain.
    My favorite:
    - Golite Chrome Dome
  • Some kind of hat and gloves are much needed except before July and after mid-August. You can always put socks on your hands, though...
    My favorites:
    - no-name fleece headband
    - PossumDown gloves

Precipitation on the PCT: rain and snow

The west coast of North America has a Mediterranean precipitation pattern, with most rain and snow falling during the cold months of the year. This pattern is most pronounced in Southern California and weakens as you move north. Nonetheless, it is typical to have at least several days of rain and/or snow during a 4 to 5-month thru-hike. Late-season snowfall is possible in the Southern California mountains through mid-May, and localized downpours may occur in the mountains throughout the summer. Rains begin to return to the Cascades beginning in mid-August and become increasingly likely as you move into Washington in September. Extended rains are known to occur in the Washington Cascades beginning mid-August.

Rain and snow on the PCT in 2009

The only precipitation from Mexico to Kennedy Meadows was a very brief downpour in the Tehachapi Mountains. Beginning at Kennedy Meadows we had unseasonably low temperatures and high precipitation (both rain and snow) in the Sierra Nevada that tapered off by Echo Lake. There was no more rain until Mt. Jefferson, Oregon, where it drizzled nonstop for over a day. From there to the Canadian border it briefly rained a few times.

Gear for dealing with rain and snow on the PCT

On the PCT rain and snow usually passes quickly enough that gear for long-term deluges is unnecessary — until you get to central Oregon. Until there, I think a sturdy reflective umbrella is optimal (the Golite Chrome Dome). From there you will need one of the following:

  • a poncho with or without a rain skirt or rain chaps
  • a waterproof rain coat and either shorts (if you don't mind getting wet) or rain pants

If I did it again I would have a poncho (not a poncho-tarp), rain chaps, and gore-tex socks sent to me by central Oregon. I would carry a Golite umbrella again the whole way. This is among my favorite pieces of gear. If you plan to use trekking poles in Washington, consider getting rain mitts to keep your hands from freezing in the rain.

Shelter

The ideal shelter for the PCT is lightweight, quick to set up, and doesn't have to be put up every night. Cowboy camping is a good way to save time over much of the trail. A bivy sack with an integrated headnet is one way to go, allowing you to sleep under the stars even when mosquitos are out. However, sometimes you'll feel confined when the mosquitos are buzzing all around and you can't easily eat inside the bivy. When a shelter for rain is needed, a generously cut tarp is better than a minimalist one, since the rain protection is better and you'll be able to sit up, eat, and pack much easier underneath it. If you want integrated rain protection and mosquito protection, something like the Zpacks Hexamid is probably optimal. If a fully enclosed shelter such as a Tarptent is your only mosquito protection, you may find you sometimes need to dry it during the day, which takes up some time.

Snow in Southern and Central California

Even if no fresh snow falls, you will certainly encounter snow on the north face of San Jacinto in Southern California and abundant snow in the Sierra Nevada between Kennedy Meadows and Donner Pass. Most thru-hikers carry no special snow gear except an ice-axe (if that) and get through fine. However, it can be quite uncomfortable to walk through miles of snow with just running shoes on your feet. If I did it again, I would take my Rocky gore-tex socks, or my Integral Designs vapor barrier socks. Another interesting option is to make an oversock out of tyvek or nylon that goes over the entire shoe, then clamp it down on the bottom by wearing Kahtoola Microspikes. However, this is probably overkill.

The thing about snow in the Sierra is that even if you have the gear to keep your feet warm and dry, you still have to wade across numerous creeks, getting your feet completely soaked again and again. With the gore-tex socks, you could have a dry pair of socks handy and slip those and the gore-tex socks on beneath your sopping wet shoes after every creek crossing. Also, you can help your shoes dry more quickly by taking a minute to squeeze water out of the tongue and other padding. This speeds up drying by a couple hours.

Dew and condensation on the PCT

While rain is generally rare, dew is common on the PCT in valleys and gullies and on or immediately next to meadows. In these situations it is a good idea to set up a shelter. Condensation is greatest in fully enclosed shelters like Tarptents. Many people end up drying their out during lunch stops, which takes up time. Under tarps or in bivy sacks you will probably not encounter any condensation issues at all. The air on the PCT is almost always dry except for the northern Cascades in late summer and early fall.

Mosquitos on the PCT

In 2009 mosquitos were active between June 14 and August 4. For most people, the mosquitos are worst in the central and northern Sierra Nevada and in Southern Oregon. Throughout the smaller ranges of Northern California they are usually not bad. Mosquitos usually taper off quickly after the Three Sisters but may briefly reappear in a few places before finally disappearing for good.

Gear for dealing with mosquitos

You'll need a generous amount of DEET, but most people tire of putting it on themselves every few hours. A mosquito headnet is a good idea, and having a shelter that allows you to eat inside, away from the mosquitos, is very nice.

Photo album: PCT weather

Typical umbrella weather. I used the Golite umbrella almost every day.

Cowboy camping in the desert. I slept under the stars most nights.

Approaching snowstorm in the southern Sierra.

My snow shelter.

The trail up Mt. Whitney. In conditions like these your feet are likely to get cold and wet.

Thru-hikers warming themselves around a fire at Crabtree Meadows.

Forrester Pass — one of the places you'll wish you had an ice axe.

Climbing back onto the trail after a small slip.

An ice axe is better for these conditions.

One of many bitter cold creek crossings.

A particularly steep pass approach. C.A.M.P. Corsa ice axe.

Dew in Evolution Valley.

A risky idea: crossing Bear Creek in Crocs while holding both poles in one hand and boots in the other.

Snow cups by Banner Peak.

Field of snow cups on the approach to Donahue Pass.

Cowboy camping with a bivy. The mosquito net is suspended from a branch, giving me a few inches of mosquito-free space over my face.

The pleasures of cowboy camping.

Thru-hiker tells of difficult weather in register at the California-Oregon border.

In mosquito country.

This is where mosquitos come from.

Fog and drizzle on Mt. Jefferson.

Trying to keep warm in the cold drizzle. Wearing a Mountain Laurel Designs cuben poncho-tarp.

Thru-hikers dry out bags and tents after a high-condensation night.

Foggy morning at the Canadian border.