Lisbon vs. Catania (Sicily)

Are you citizens of a European Union State?
If you are not, tourists can stay only up to 90 days over any rolling 180 days period in States part of the Schengen Treaty zone (both Italy and Portugal are part of Schengen).
If you want to relocate there long term, it's not like moving from California to Texas. There are immigration rules to comply with. One first needs to inquire on Immigration rules for Portugal and Italy, to see if one qualifies (and how).
Also, what are your language skills? Do you speak either language already? The language barrier is an important element to consider, especially if you do not intend to stay in cosmopolitan cities, or heavily visited locations, where some English is known.
Regarding the cities you are asking, I've only lived in Florence (for almost 30 years), and I've only visited Catania (which I don't like, but there are nicer towns nearby). Don't know Lisbon. But before you consider moving there, you should visit for an extended period (maybe a long vacation in an apartment) and see for yourself.

As Roberto said. Plus:

To relocate permanently, you must begin the process at the consulate of the country you choose to live in. It can take quite some time. Lots of paperwork, proof of income/funds without working in the country, health insurance, and other things. You must reapply every year or every two years (means returning to your home country), at least for Italy.

Do you have a job currently which is offering you these relocation options?

I think public transport works a little more smoothly in Portugal, but that won't matter much if you have a car. A car will also be useful for any side trips from Portugal to Spain, since other options are flight, long bus ride, or one single overnight train Lisbon-Madrid. Both areas can be relatively cheaper for visitors than northern Italy or Spain and both offer plenty of options for exploration.

Yes - relocation is all covered by employer (U.S. govt). I speak a bit of Spanish (and French) & would attempt to learn the language before arriving. We have to decide in the next few days - very short notice!

I presume Catania area is the Sigonella Naval Air Station. That is located a few km outside of Catania in the interior.
The area is nice, with nice weather and there are beautiful beaches nearby. Very close to Syracuse and Caltagirone also. If you live on base, they have American style homes next to the base.

Those are two exciting options. There would be enough available in either of those areas to keep you occupied for quite some time. Eventually you'd want to travel farther afield, of course. Both Portugal and Sicily feel a bit isolated from the rest of Europe, so it might be worth taking a look at where you can get to from Lisbon and Catania by plane. That information appears in chart form on the Wikipedia pages of the two airports. Note that listed flights do not necessarily run every day.

Lisbon airport
Catania airport

A plus for Lisbon, for me, would be the availability of non-stop flights to Madeira, which is a very nice destination pretty much all year long.

With some Spanish and French in your background you'll have a leg up on learning either Portuguese or Italian. I've taken classes in both languages, and I don't think there's a significant difference in their difficulty.

You might take a look at historical weather data for the two cities. Wunderground.com is good for detailed data. You can find high-level data in chart form on the two cities' Wikipedia pages:

Lisbon (scroll down for weather chart)
Catania (scroll down for weather chart)

My layperson's interpretation is that Catania is much hotter in summer and is drier year round. Lisbon is generally more temperate; it will have more rain and will be cooler in the winter.

I don't know anything about the comparative cost of living, which could also be a deciding factor.

After taking all the above points into consideration there is one other factor in favor of Lisbon. That is that, if you are so inclined and want to visit other European countries during your time there, it is much easier and probably less costly to get to other countries from Lisbon.

I would lean in favour of Lisbon if you are thinking of exploring other parts of Europe. Being a capital city it has extensive direct air links to all corners of Europe.
Sicily would be wonderful if you were looking to immerse yourself completely into life here and exploring every inch of the island. Otherwise, to venture further, and I think it would be a case of getting used to the 'connecting flight'.

Edited to add: These destinations are from Catania. Sorry for omitting that most critical information.

I just checked skyscanner.com and found January non-stop flights to all of the following countries. I didn't dig down to see which specific cities were available or check the frequency of the flights.

Malta
Italy
Romania
Germany
Hungary
France
Netherlands
Poland
Spain
Switzerland
United Kingdom
All those are priced at less than $100 one-way, buying today for sometime in January.

And considerably more expensive:
Austria
Turkey

I've been to Sicily but not to Portugal. Loved Sicily. Tke that into account as you consider my thoughts.

Winter on the Atlantic coast sounds harsh to me. Sicily is milder. Atlantic beaches are cold. Mediterranean beaches are warmer.

With a car, you'd take the overnight ferry to the Naples and drive onward. Not so convenient for a weekend, but for a 1-2 week vacation, get a pleasant night's sleep and you're ready to go . . . From Lisbon, it's 4.5 hours driving time to Seville, about 6 to Madrid.

Thanks ACraven, Chani, DJP SYD, Carol, Roberto, Zoe, Laura – your advice is much appreciated.

Lisbon is really only accessable to the rest of Europe by plane. You can drive to other parts of Europe but it's not easy or convenient.

There are multiple ferry options from Sicily which gives you driving and trains, as options to flying, to get around Europe.

As for the language. I've never attempted Portuguese but you can speak Spanish to Italians and they'll understand, many words are virtually the same (e.g. senorita, senorina). There are differences but I found myself confusing Spanish and Italian words, because they are so close, then realized people would understand either so it didn't matter. I've found Italians are the most appreciative of any attempt to speak their language of any country I've been to in Europe (Quebecois really appreciated my feeble attempts at French too).

I have been to Italy several times and Portugal twice. I love both countries. However, I have never been south of the Naples area in Italy. I do know people that lived in Naples (they worked for the US Navy). They enjoyed living there, but were advised before moving there (this was about 15 years ago) not to take an expensive car, stereo set or expensive TV, etc. They complied with this advise and did fine in Naples, but did comment that crime was a real problem in the area. Not sure if this would apply to Catania?

I visited Portugal in 1985 and then in May 2016. Lisbon had grown quite a bit, but still had the charm that I loved in 1985. This time I visited Northern Portugal, Porto and did a Douro River cruise, which was wonderful.
Again, we found the Portuguese people to be wonderful. Portugal was inexpensive, the food was great and sights are awesome. Compared to Spain and Italy, the Portuguese people are even friendlier and more helpful.

Our daughter spent 3 years at the NATO base near Catania. We visited her there. They lived on base. It was typical of military installations overseas. Their place had 2 bedrooms, 2 baths and 2 stories.

While her husband was at work, she drove us around to many of her favorite places in Sicily. We absolutely loved it. Not being one to stay put on base much, she and her daughter (3-6 at the time) and sometimes her husband drove or flew to many places in Italy and the rest of Europe. The flights from Catania didn't thwart them at all.

We've also been to Lisbon. We spent a week in an apartment there in the Alfama district. We found the city unique and beautiful. And we loved the Fado.

I don't think you could go wrong in either location. Both would provide great experiences, assuming you get off base. Fishing is easily possible in both places. I'm guessing you are comparing the facility details of the military installations in both locations, so that could be a deciding factor.

As others have mentioned, Lisbon (population 545,000) will be both colder and a bit more convenient for getting to other places in Europe. Catania (population 316,000) will be warmer and more convenient for getting to other parts of Italy and to Greece. And the active volcano, Mount Etna, is close to Sigonella and Catania.

The food is good in both places, but we preferred the food of Sicily. That's with one Sicily caveat. Our daughter took us to a place quite close to the entrance to their housing area. She and her family loved it and went there often. We thought it was ordinary at best.

And with one for Lisbon -- the cakes are divine. The pasteis is great, but I particularly liked the alentejo cake.

I'm sure our daughter would be happy to discuss her experiences in Sicily with you. PM me and I'll put you 2 together if you want.

So when you decide, let us know if it will it be bom Dia or Buongiorno.

Thanks Brad, Geovagriffith, and Lo.

Just found out today that it's LISBON! Ecstatic! So, Lo, I guess it will be "Bom Dia" - and certainly time to start learning Portuguese.

Again, I really appreciate everyone's input. Happy 2017 to all!

Congratulations, Catherine. What a great year you're going to have.

Now, for the practical stuff - let us know your address as soon as you can so we can start planning to visit you ☺