THOUGHTS: Berlin in December ?

Munich and smaller towns for the markets perhaps.
There is an article on the Christmas markets on the forum. Just enter search,to find it,

My family was stationed in Schweinfurt and every place has their markets, they ventured out on weekend s and explored many.

PS, I love Berlin and have been twice, once on RS tour once independently.

My wife and I spent 8 days in Berlin in 2014. We loved it. There is such a variety of activities. We didn't do everything that we wanted to and are looking forward to going back some day. 6 years ago Berlin was an extremely affordable city. I don't know what prices are like today, but Berlin is definitely worth a visit.

If I'm going to Europe again that late in the year, I'm going south. Berlin & London are pretty far north, and weather can be a little cold and unsettled that time of the year.
At least in Bavaria and in the Austrian Alps, we've got the incredible snow covered mountains as sceney.

Your first and last days are going to be just getting to and from the airport and on the first day, just trying to stay awake which means you have 7 days. At a time of year when some things are closed, I would be tempted just to visit one country rather than spreading yourself too thinly. Maybe London and York or Edinburgh?

I have been to Berlin in mid December and there was plenty to keep us occupied for 6 full days plus travel days. It’s a great city. We had a light dusting of snow one day, but otherwise, it was dry.

Who knows which airlines etc will still be in business by the end of the year. We aren’t planning any holidays until spring 2021 as we don’t think the situation will be fully resolved until then.

Berlin & London are pretty far north

This is probably the first time I've heard Berlin and London being referred to as pretty far north. :-)

London is farther north than Calgary, Alberta. Berlin is even more to the north.

We were in Berlin Dec 23 to 27 last year. Many places closed on Dec 25 to 26, So, check their websites for opening hours during holiday.

Even though traveling to Europe over the holidays sounds magical, we wouldn’t do it again. So much was closed, restaurants, museums and there were crowds too. Decorations were pretty though.
We were in London and Rome.

I've read the Vienna has xmas markets thru New Year's, and is beautiful with all the holiday decorations.

Safe travels!

London is farther north than Calgary, Alberta. Berlin is even more to
the north.

Yes, and they are also north of Madrid, Miami and Cape Town. But by European standards they are not that far north.

I am planning a trip to Europe during christmas time. . . . . The trip would be from 12/25/20 to 1/2/20 ( Landing the 25th at 8:00 am ).

The first thing I would say is landing on 25th December is not a Christmas trip. Most of the Christmassy things to do and see are in the weeks leading up to Christmas. Many Christmas markets close on the 24th, or even 23rd, December; only some stay open until the New Year. 25th and 26th are stay at home days. If you have a hotel with a Christmas package, hotel, Christmas meals, perhaps some entertainment, that is good. 25th and 26th are good winter walk days.

I would recommend shifting this earlier, returning on the 26th or 27th.

If you want to see the London New-Year's-Eve fireworks, you need a ticket: https://www.london.gov.uk/events/2020-12-31/london-new-years-eve-fireworks-2020