I prefer about 2nd to 3rd set of true leaves. Some may wait longer, you have to decide what you are comfortable with the smaller they are the more delicate they are but the bigger they are in the container the harder they are to get out of the container. Bigger plant, bigger roots to many plants equal tangled.

Also depending on what it is I will make sure there is not going to be any frost. I agree the temps are great for transplanting!! Though I know we will have another good freeze before it is all said and done.

Second set of true leaves (sometimes I transplant first set of true leaves) and then smack them into the ground HOS.

yes, it looks crazy, but your sprouts are NOT weak.