Sleeping Bag Rating

Everyone else isn't camping in the same places you are. You'll have to provide more details about location/conditions if you want people to chime in.
You should consider clothing too. Are you using insulated clothing or just that merino thong?

A better question would have been what rating would you suggest someone get for their first bag? I may hike the Buffalo River Trail this winter, so I would be likely to see 20F and could see 0F. I would probably sleep in a Patagonia Capilene 3 base layer with SmartWool Socks and a SmartWool Beanie.

Whatever you buy, don't buy "cheap". Get something decent and in the range of what you're expecting to experience. I have 3 bags and one quilt for different times of year. I got a 15* mummy bag for down to single digit weather. WM has conservative ratings, and in addition to base layer, I also have bought several insulated pieces since spring. This should extend *my* range down around zero. Others may sleep colder or warmer. This is something everyone needs to find on their own. The beanie is good. Keeping your head warm will keep your body from wasting valuable warmth. The hat doesn't work for me though. I learned a long time ago I need something like a balaclava/ski mask to hang on to my head through the night.
This is a good time to get out on a regular basis. As the temp drops, you can see how you and your gear handle the lower temps. If you're unsure, try it in the back yard. You have the safety net of a warm house and your own bed nearby.

"January average temperatures range from 35° to 4° F"
– http://www.netstate.com/states/geography/ar_geography.htm

I'm definitely happy with my Montbell bag. The WM bags aren't big enough for my build. I like the idea of trying it out at home as the temperatures start to drop. I'll pick up a balaclava too. Thanks!

Roman,
Most WM bags don't fit me either, but there are a few. I'm good with anything 6'6" and 66" of shoulder girth. Check out the Badger, Sequoia, Kodiak, and Ponderosa.
http://www.westernmountaineering.com/index.cfm?section=Products&page=Sleeping%20Bags&viewpost=2&ContentId=27

Paul,
Don't believe everything you read. Arkansas sees negative numbers too. Not often, but it can get get down there at times.

I didn't realize they made a 66" girth. I was able to zip up a 63" girth yesterday, but it wasn't very comfortable. lol

I have the bag u bought and really like it. I think it is true to its rating, with light base layer on, with hat. I also think it is a good all around for all but mid summer, just use quilt style, or sleep on top of with liner/sheet. Anyway, you have to decide how cold/warm you will be camping in to determine optimal bag. Do you want two bags/ summer and cold? Or only one? IMO, you could go down to about 10 with the bag you have, layering up appropriately. I can't stand being cold at night, so I always use that bag year round, and am too cheap to buy summer weight bag. I have a fleece liner I use for hot camping.

Wow. That link also had record low:
Lowest Temperature The lowest temperature in Arkansas, -29°, was recorded on February 13, 1905 at Pond

Nevada record low is -50°, but that was on the other side of the state at San Jacinto, 1937.

I have the same bag and love it. I want to get a summer bag, but just haven't done it yet.