Hello fellow Mt. Whitney hikers. This question seems to come up every year. My friends and I have a day permit for the main trail on July 2nd, and I too am concerned about the snow. In 2006, a heavy snow year, we attempted an overnight hike on Whitney in early July, and didn't make it much past the "cable section" due to snow and bad weather (snow and lightning). In 2007 we went later in July and made it to the summit no problem. Since there is no way to predict the weather or snow melt, just keep reading this board every day until your hike. People will post their trip reports and photos. You should have a good idea of the trail conditions a few days before your hike. However, you will not know what the weather will be like until the day of your hike. Good luck on your climb and I too hope to make it to the summit in one day so I can buy the tee-shirt that says "I hiked Mt. Whitney in one day".