My wife and I hiked Whitney as a day hike in September of 04. No snow on the trail except for what fell during the hike, which melted quickly.
You've got a lot of good info already. Get your permit early. You have to commit to the day you're going. Hope for good weather.
The trail is beautiful and well marked, easy to follow (the early parts are like a highway). The scenery is spectacular. It's all very hikeable in trail runners.
Key lessons we can share:
Preparation:
>Get fit. Do a lot of vertical locally before you go.
>Bring a water filter or other purification. There is water at Trail Camp, and you'll want to fill up there.
>Make an acclimatization plan. Ours was: Tenaya Peak (10K), Mount Dana (13K), rest day, Whitney. Worked well. We summitted and felt good. Rangers will tell you that the people that suffer are the ones who drive or fly in from sea level or locales <5000', and then try Whitney the next day.
Hike day:
>Start early. The day permit is for the 24 hours midnight to midnight. You can start as early as you want. We started about 4:45 AM by headlamp, which is typical. If you're in doubt, or plan to hike at a slower pace, just start real early.
>If you're looking for a good early breakfast, Denny's in Bishop is about the only choice. It's the only 24 hour food on the East side.
>A lot of people, I'm told, sleep in their car at Whitney Portal. But with the seriousness of the bear problem there, I'd rather not have my breakfast food up there. Give me a restaurant, and a little extra driving time!
>The weather can change quickly. We had snow squalls during the day. The Summer snow doesn't accumulate a lot, and the trail is level and carved right into the mountain, so you won't need crampons. When it started snowing, I asked some locals for advice. They said, don't worry about it, the trail is easy to walk with snow on it. They were right. The one watchout area would be the switchbacks above trail camp. If there's a lot of snow, or a freak ice storm, they could be tricky.
>Totally respect thunderstorms. People have been killed on Whitney by lightning in every month of the year. If there is a thunderstorm coming, stay down at a safer location. Don't be on the summit ridge.
After the hike:
>You might be tired. I don't know if you're camping or hoteling, or where you're staying, but a hotel room in Lone Pine that night is nice to have. We were camped in Yosemite at Tuolomne, which is about 3 hours drive away. We got off the mountain at a good hour (7 PM), but we really didn't feel like driving 3 hours, so we grabbed a room for that night in Bishop, and headed back the next day. (Bishop is a nice place, too. Take in the Galen Rowell gallery there.)
It was my first visit to Whitney. There were a couple things that were a pain in the a**:
>It was hard to find the Ranger station in Lone Pine to pick up our permit. No light on in the building, poorly lit and partialy obscured sign, etc. We drove back and forth and finally stopped in a hotel to ask where it was.
>Poor signage at Whitney Portal. It was unclear which parking lot we should use. Once figured that out, and parked, it was damn near impossible to find the trailhead. There were big clear signs all over the place for the stupid store, but none for the trail. So we joined several other people who were also milling around with headlamps looking for the trail, and we finally found it. The actual trail is marked with a lousy little sign, with dark brown writing on a light brown background.
I don't know your trip plan, like I said. If I was doing Whitney again, I'd probably hotel it in Bishop, and drive up to the Portal in daylight the day before to get oriented.
Have fun!
TCD
