In early September it can be very cold at Whitney Portal and more so at the summit of Mt. Whitney. The weather often begins to change in the mountains in September - colder. It can drop to below freezing temps at night. You need to ask yourself if you had to, because of injury or some other reason, spend a night out in the open on Mt. Whitney, with no tent or sleeping bag.
I always carry enough on my day hikes in the Sierras to be able to survive at least one night out at high altitude if I am forced to do so. Layering clothing is the key to comfort and if necessary, survival. You can always add or remove clothing as conditions change.
Here is the basic survival clothing and other items I carry or wear for a Summer day hike:
Light weight hiking shoes
Long sleeved shirt
Fleece cap and gloves
Waterproof rain pant (if rain a possibility)
Gaiters (if rain a possibility)
Waterproof bivvy sack
Extra, high-energy food bars
Sun screen cream
Map and compass
Cell 'phone (sometimes connections are possible where I hike)
Personal first aid kit
As Summer ends, I will add:
Down jacket, with hood
Long underwear, top and bottom
One change of socks
Heavier hiking boots
Regardless of the season, I can add or remove clothing in order to maintain a comfortable body temperature.
Why all that stuff? I learned the hard way when I would have probably died without the extra clothing, during several unplanned bivouacs in the mountains.
Edited by Bob West (08/09/17 08:35 PM)