I started the hike mid-afternoon but as the trail is practically a fire road and having a fully-powered headlight I anticipated doing a night hike on the return trip from the summit. The reason for the doing the return trip as a night hike was to see if the comet is still visible.  The weather was clear. There were no other cars parked at the trailhead so this was a real solo hike as I met no one going up nor coming down.  The hike up to the summit was uneventful with a brisk walk and stopping by to take pictures and short breaks. Starting at 1500H I got to the summit at 1720H and I signed the register and took more photos and rested until 1800H sunset before heading down. Near the summit on the mountain slope was snow but there is none on the trail itself – one would have to leave the trail to reach the snow. Heading down, shortly after it got dark I stopped and scanned the sky to see if the comet was visible. Unfortunately it was not although I was able to locate Venus and Arcturus and the location where the comet should have been visible. The night clouds was probably the reason it was not visible – although the night sky had stars, there were clouds that obscured some of the stars. The hike up took two hours and twenty minutes and the hike back to the car was one hour and forty minutes. And with that the Summer AZ Challenge is complete.