Hi Marie, here are my answers, I'm sure others can provide input as well. By the way they post a very good HR runner's manual every year, but you have to remember that they reverse directions so you may want to find one going the right way if you get in.  Here's a link:  http://hardrock100.com/HRH2015runnersmanual.pdf

What were the temperatures during the day and the night?

I actually had a pretty good weather year, it was kind of warm during the day, but not too hot.  I wore a short sleeve shirt most of the time during the day, even on the passes.  But at night it got kind of cold, I put on a long sleeve and also a rain jacket at times.  The wind/rain made it feel colder.  The big issue is lightening though, especially up high. (See the runner's manual).

How did the temperatures compare to a "typical" Western States day?

I'd say that WS is way hotter than HR.  At abt. 8,500 ft the highest elevation at WS (which you only hit once in the beginning) is a little higher than the lowest point at HR (which you also hit only once at Ouray).

Were you adding layers on top of the peaks and passes, or just tough it out?

During the day I didn't need to add layers on the passes, maybe a little cool, but also kinda nice.  I only added layers at night and especially on the passes at night.  But also during the thunder squall I hit going up Bear Creek trail.

Did the rain feel good, or was it very uncomfortable?

I'd say because I was really beat up, the rain was uncomfortable.  Plus it was night and it was really really windy.

Any snow on the trails?

I had just a little bit going down the north face of Virginius Pass.  You can see the exact snow I had in the video I linked above since it is from the year I did it (2014).  That is where the Kroger's Canteen aid station is, when I got there they were really great and had a fixed rope you could hold on to.  The fixed rope was there to slow you down and keep you upright.  It was like you were going straight down. Buy the way, I had gloves with me because I knew there was a little snow on the course, plus gloves are a tiny thing to carry, but can really help regulate body temps.

Can it actually snow during that race (has that ever happened during a HR race - I know it happened during a Western States a year or two ago, right)?

I'm sure it has happened at HR, but again the worse thing is lightening.  Not sure about it actually snowing at WS, but the year I did WS (2011) while it didn't snow, I had to run on the top of deep snow for I guess about 15 miles after Emigrant Pass and they even re-routed us. Then it got hotter than hell later in the Canyons.

What shoes did you wear, and how did they work for you?

As always, I wore road shoes, Asics Gel Nimbus.  But I did make sure the tread was good, a newer pair, they were great.  I also wore my Dirty Girl Gaiters (full disclosure...   Rattlesnake pattern).   "I walked 47 miles of barbed wire...  "

Awesome RR Sandy! Thanks for sending me the link! And hopefully we can share a few miles at Grindstone! See you in 9 days!