Planning a vaca end of Nov/beg of Dec - Azores, Madeira or mainland Portugal?

I just sent you a private message with a link to my Azores guide. It may help you make a decision. You will enjoy any choice you make!

I've been to Madeira twice. It is beautiful. There are many, many miles of level walks along the irrigation ditches with fabulous views. I imagine there are more adventurous options, but you'd need to check on that. What it doesn't have is sandy beaches, so if that's important to you, you need to look elsewhere or plan a day-trip to Porto Santo.

I've linked to the Wikipedia entry, where you'll find a weather summary chart. If you want to see actual historical day-by-day variation in temperatures (a good idea), you can probably find that info on wunderground going back 10 or more years. The temperature is normally moderate year-round, though I see that temperature spikes are possible mid-summer. The problem for you is that December is the wettest month of the year, with measurable rain on 13 days, on average. Madeira is rainier, in general, than one might expect for an island so near the equator. Of course, that's why it's so green and gorgeous.