Fastsky is right. ABC/N engines need to get up to operating temperature to properly break in. This type of engine has a slight taper at the top of the cylinder. When the engine gets hot, it expands to allow the proper clearance. If it doesn't expand, your break-in may actually shorten the life of the engine by wearing the parts out faster. Beak in ABC/N engines only a couple clicks off the peak setting.

Now, to answer your question: there's no difference in ABC/N engines and ringed engines when it comes to weather. Be aware that cold, damp air may cause you engine to run a little leaner than normal, and adjust the needles accordingly.

Dr.1