Hey - I just joined up the other day. Today was my second try with my off-set smoker. I went with tenderloins again, thinking I will save my pennies for the big cuts until I feel a little more confident. Anyway, I used lump charcoal, got a good fire going and got to about 245 in 20 minutes or so (CT). Put the meat on at 2pm, was able to maintain a range of 225 to 255, frustrating that it fluctuates so much. I probed at 2 hours and had 115 IT. I added lumps and one more wood chunk (apple) and by 6:30 pm, was only at 131 IT after many more charcoal additions. Long story sort of shortened, I am finishing in the oven... and my wife wants me to ask you guys if you make house calls! To relate this to my title (cold weather smoking) my humble theory is that mother nature out did me by dropping the outside temperature from 65 at 4pm to about 35 at 5:30... making very hard for me to keep the heat up in the smoker. Does that sound reasonable? It's darn chilly out there.