Barcelona--getting around in December

I would recommend just taking a taxi directly from the airport to your hotel. Taxis in Spain are relatively low cost, yet are well maintained.

For getting around the city, the metro with a T-10 card is the way to go.

There are at least two people on this forum that are or were Barcelona residents, one of them (Carlos) has already replied.
Most of the year visitors on this site seem to walk around Barcelona during the warmer months, and take taxis if the distances make walking infeasible.
You'll want specific information on how uncomfortable the weather will make walking in December.

Regarding December weather in Barcelona, it's actually quite mild compared to other parts of Spain, due to proximity to the Mediterranean. I last was there visiting family in December 2018 and was like 12-15 C most days, (like upper 50s F). PS there is none of that miserable winter wind one finds in cities like Zaragoza (or NYC I presume).

We were there December 8-10, 2018, the temperature was not bad at all, light windbreaker and long sleeve shirt was all we needed coming from Colorado. We did quite a bit of walking around at night with very little problems. December is a wonderful time of year in Barcelona.

PSS: Make sure to visit our Santa Llucia Christmas Market in Dec., it dates back to the 1700s! It's located adjacent to the Cathedral, the one right in front of the Barrio Gotico. Official Website: https://en.firadesantallucia.cat/

Thanks so much. We are staying in the Gothic District and the market is already on our list. I think we will be able to walk most of the time, except up the Park Guell and Sagrada Familia. We will get a T10 and take the Metro there.

Any other thoughts on the airport? Cab is still best for two people with carry-ons only?

It depends on where in the Barri Gotic you are actually staying. I've used the AeroBus both times I flew into Barcelona, most recently this past March. They leave every 5 minutes. If there's standing room only, you can let others board and be at the head of the line for the next bus. It's comfortable and pretty fast. The last stop is Placa de Catalunya and the Barri Gotic starts there and is all downhill to the sea. So it's just a question of whether your hotel is a 5 minute walk or a 25 minute walk. If it's a long walk or if it's raining, you can get a taxi where you get off the bus. The bus is easier than the metro to get into the city, but you'll want the metro pass for sightseeing. The T-10 is definitely the way to go, you can use the same one for both of you.

I will be in Madrid and Barcelona in September. I'm reading conflicting information about ride share options. Is there still Uber or something similar? I'm mainly thinking about getting to the hotel from the airport/train station and to a restaurant reservation that would be about a 30 minute drive. If not, is there an app for taxis where I can pay with a credit card?

As of yesterday Uber's website said it was not in Barcelona. They are in Madrid. Here is the link to all the cities Uber serves: https://www.uber.com/global/en/cities/.

Also, as far as the distance from Placa de Catalunya (where AeroBus drops) is 850 meters. It's in the middle of the day and we only have one bag each, one rolls and the other is a back pack. We are glad to walk if the weather is nice, since it's downhill. If weather is inclimate, we will cab it. Thanks everyone--now to start a new post regarding Paris :).