i'm happy people are chiming in with thoughts about safety and all that, but as i think you know, the tahoe tim trail is one of those that, without snow, you'd have to work VERY hard to get lost on. i'm planning on thru-hiking it again in july or so, and i'll probably bring the trails unlimited map, and no compass, gps, spot, or any of that. i mean, if i didn't need any of that in 2700 miles of the pct, i don't think i'll need it for 165 miles of super well graded, super well marked trail around tahoe.
"Whilst you might well go the entire rim without snow, there is not a month of the year that Tahoe does not have snow. "
given the snowfall (lack of), i sure think things will be pretty dang melted out by july for sure. there hasn't been significant rain/snow (other than a bit last weekend) in a coupla months. you might be able to find a patch on north facing shaded spots late in the season, but there are definitely a number of months with no snow on the ground in the tahoe basin. if you are there in june, you might find some for sure, but in july, i'm thinking not much!
the biggest hazard on the TRT (in my experience) is getting run over by mountain bikers going way too fast around blind corners!
i'll post my gear list when my trip gets closer. i'm trying to go really light. but yes, make sure you are ready for:
1. some longish stretches without water
2. mosquitoes (depending on when you go)
3. summer thunderstorms (most likely in the afternoon, but could rain in the evening also)
other than that, it's an easy, lovely trail.