High Sierra Topix

I'm thinking about doing the Rae Lakes loop out of Cedar Grove in late September. Partly because that's my birthday and partly because there are no permit quotas after 9/19. I'm just wondering what conditions to expect. Has anyone hiked it at that time? Given the elevation, is there much risk of snow then?

I say all of this with the giant caveat that nobody can predict the weather, but you will probably be ok. In fact, I love post-Labor Day backpacking because the crowds and the bugs are gone, although wildfires and smoke can be an issue in dry years like this one. Normally the Sierra doesn't get it's first major storm until early to mid-October, but there have been notable exceptions. Pay close attention to weather forecasts before you go out, and don't go if they're forecasting an early season storm. Generally you can be very confident in forecasts about 3-4 days out. But even if you're not going to get hit with a blizzard, you should be prepared for cold nights and significantly less daylight than you would have in July and August.

1) Nights can get below freezing in September. But nothing crazy uncomfortable if you're prepared.
2) There's often 1 snow event each September, but it'll drop a few inches and then quickly melt. Last year on September 29th, we got 3-4 inches and it closed 108 & 120 for a day or two.
3) Crowds are almost never gone on the Rae Lakes loop. Saw probably 200+ people on the JMT there last year on September 7th.

We did the Rae Lakes Loop from Kearsarge Pass the second week of September last year. Over our 6 days of hiking, we had near perfect weather - cloudless days, no rain, and wonderful temperatures. We did have a freeze the first night at Kearsarge Lakes, but otherwise, above freezing temperatures at night. Despite being off-peak, it still felt like there were quite a few folks on the trail, particularly around Kearsarge Pass where there were several folks going back to finish portions of PCT or JMT resupply. Last year was also a heavy snow year, but by that time, there was definitely no snow on the trail, but scattered patches around. Strongly recommend the side trip to 60 Lakes Basin.

Thanks for the replies! With some preparation it sounds like it'll be doable and likely quite lovely.

September is our favorite time to backpack in the Sierra. Less people and less bugs. With that said you do have to pay attention to the weather. We did the Rae Lakes loop in the second week of September 2016. The second night we got a rather cold rain, the next day is was very cold, then the next night it got down to 12 degrees. We heard a story of some German backpackers doing the JMT that were not carrying a tent. Their down sleeping bags got wet during the cold rainy night. The next cold 12 degree night was rather scary for them with their wet down bags. We heard they left the trail. Not sure if it was true as we heard it second hand.