Mt Whitney Zone Forums General Discussion Historical Weather?

Any idea when is the warmest time on Whitney Portal and the mountain? First week in August?

timf, I'm sure there's some variation but last year when I dayhiked it on August 18th it was pretty doggone warm. I never even put a light jacket on - shirtsleeves all day. I think any time in August has great chance of being pretty warm. I watched the summit weather on-line just about every day through August, and it was nice almost every day.

The best place to get historical temperature data is the California Water Resources Board. Hit the earlier link and fiddle with the url.

http://cdec.water.ca.gov/cgi-progs/queryF?CWD

Cottonwood Lakes Reporting Station is the most reliable location near Whitney Portal.

Hmmm....my last August trip in '02, it was a balmy 9* F on the summit with 30 MPH winds. The weather is so unpredictable in the Sierra. It was a hell of lot warmer on the summit in May 2007...by about 30* F. I had with me I've had a trip where their was a 30% possibility on the first day and it rained all 4 days we were out.

You really have to be prepared for the worst or you can pay an awful price for your gram counting.

Actually, another good source (some free, some not) is the National Climatic Data Center (NCDC). I'll check on that and let you know.

Updated - OK ... Independence was the closest station I could find to Lone Pine, which will should be substantially the same as far as mean temperatures and all that.

So here's the link to the free PDF of the climate summary for Independence. Hope that helps.

CaT

Agreed, be ready for anything. My first Whitney summit was by far the warmest, early August in shorts and t-shirts. Other August trips have included sub-freezing temps and strong, cold winds. Early September can be nice too but things change quickly.

Typically August is the warmest month.

The other comments notwithstanding - while it's prudent to be prepared for anything, the weather in the Sierra is perhaps the most stable of any major range in the US. The exception to this might be an El Nino year, when the incidence of afternoon t-storms may be similar to that found in the Rockies.

Watch for long-range forecasts if you're doing a multi-day hike and you can greatly reduce the chances of being caught up high in summer storms.

Okay, make that "substantial variation". And always be prepared for extremes. I had at least 5 pounds of winter clothing in my pack that I never pulled out the entire week hiking Whitney and environs in mid-August, but I'm not dumb - I was ready JIC.

I usually take all the warm gear in the car to the trail head, but check the weather forecasts at the last minute. If it is clear, warm, no wind at the trail head, and if the weather forecasts are clear, I'll leave the extra gear in the car.

Otherwise it gets packed into the backpack.

Bulldog,

I've been carrying the same stuff during the 3-season for the last 5 years or so with little variation. I've froze my rear end once...on the summit at dawn in '04 and one night in October 2008 at 11,000' when I was too lazy to carry an extra sleeping pad, which was in the car at the trailhead...that's it. Last summer, I don't think I used my 3-season down jacket but once...on the summit of Mt. Whitney. It does make one heck of a pillow.

About the only adjustment I make is to add one of my microgrid fleece tops and an extra pair of mitts for pre-dawn 14,508' summits...that and what flavored alcohol goes up the trail. The nice thing about backpacking is that sleeping bag is one heck of a piece of extra clothing.

Labor Day weekend 2008 encountered 70 MPH winds at Trail camp. Reported to be 90 MPH winds on top.Blew down Tarp tent repeatedly and almost knocked me down several times.Turned me sideways repeatedly.But it was really warm.

The only thing predictable about weather is its unpredictability.

...except when it's predictable.