Outdoor Fermentation

Since I live in an apartment, I've got no room for a carboy just sitting in the way. Therefore, for the past two brews I'd put the carboy in t-shirt/tub of water, covered it with a thick blanket, and am leaving it on my shady/windy patio.

So far the stout I made turned out okay, but would the water help to regulate temperature? Also, generally is it sound to keep fermentation temperatures around 60-40 degrees (that's the weather around my area, understandably colder at night)?

Yes the water well HELP regulate the temperature. But you want to keep the temperature as steady as you can. If it cools off at night your yeast might drop and not attenuate all the way. I ferment ales at 60-65 degrees. Maybe take a temperature reading when you wake up in the morning and see how far down the beer has cooled.

If you don't have enough room for a carboy I'm not sure what to tell you. Brewing equipment takes up space; no way around it other than just basic organization.

i think you'll see a big improvement in beer quality if you ferment it in more controlled conditions. i doubt the water is serving as that much of a thermal regulator, but put a thermometer in there and see how much it changes day to night. you definitely don't want to be ranging from 40 to 60, keep it around 60-62 ambient, you'll have a beer fermnenting around 64 in my experience with those conditions.

Well honestly it's a Scotch Ale yeast, so even in the dead of night I've seen bubbles rising. Hopefully this turns out to be a smooth, complex big beer...created from the winter night ^_^