What to wear in a UK winter

I just posted another thread about moving and packing that raised some of the questions I'm about to ask, so hope I'm not double-posting.

My more general question, though, is how one dresses for the UK winter. I've lived in a cold place before (not snowy-cold, but windy and rainy), but there it was even cold inside. I spent winter with thermal long-sleeved tops and bottoms on all the time (even when sleeping) and lots of layers. But I gather than inside is generally warm in the UK - so if one has thermals on you'd end up melting inside. Is this true? How warm does the 'bottom' layer then need to be? Would a thin cotton top be okay if you had things to put on top when you went outside? And how many layers does one need outside? Would a long sleeved cottony top, topped by a fleecy/woolly top, topped by a jacket work? How warm would the jacket need to be? And is a long jacket necessary to stop the top of your trousers/skirt getting too wet?

I have lots of questions, but I'll just leave it here and see if anyone has any suggestions - I'd particularly welcome advice from people who came from warm climates (i.e. LA) and had no experience of cold, snow, rain etc ...

I won't try to answer your questions because I originally come from a place in the US with a cold wintry climate...and I tend to run 'warm' anyway.

Just wanted to mention, though, that waterproof footwear would be a good idea.  Maybe it's just me, but I seem to be very good at finding the 'flagstones' or bricks in the pavement here in the city centre that are loose and have water underneath them when it's been raining.  Nothing like getting a shower from above and one from below!

Also (gosh, sorry, said I wasn't going to answer!), whatever kind of 'outer' jacket you can find that is 'windproof' and 'waterproof' is also a good idea.  The one I wear isn't very feminine, but I personally find the cold wind to be more of a problem for me outdoors than the air temps.  If I can keep the wind and water out, I'm generally fairly toasty without many layers underneath (which is just me, as I said)...

I would not say it is generally warm inside in the UK.  In fact, I would say because of the damp it is colder here than when I used to live in RI.  It was really cold there, the year I lived there it didn't get above freezing for two months, but because it was dry it felt less cold.  

To where in the UK are you moving Doria?  There is a pretty big difference between North and South.  Even a big enough difference between the Midlands and the South.

I would not say it is generally warm inside in the UK.  In fact, I would say because of the damp it is colder here than when I used to live in RI.  It was really cold there, the year I lived there it didn't get above freezing for two months, but because it was dry it felt less cold.  

I would agree with that. It may depend on the type of accommodation of course. Newer houses are probably going to be a bit cozier than old stone-built ones. 
I wear more wooly jumpers in the UK -- would be sweltering in the US indoors.  Also vests.  I might dress like that to get to work here in the US but then would remove a few layers once I got there. Not so in the UK.  The first things I bought when I moved to Leeds was a sheepskin jacket and old-lady non-skid waterproof shoes (K Aquaskips). Frumpy but I didn't care!

I gather than inside is generally warm in the UK - so if one has thermals on you'd end up melting inside. Is this true?

I think this depends on whose house you're going to.  My wife's godmother keeps her house so cold you can see your breath.

I've gotten used to our heat being set at 19 or 20C (66 or 68F), but when I lived in the US I'd have considered either of those temperatures to be too cold.  When I came over to the UK and wanted to set the heat at 22C (72F), my wife thought that was extravagant.  Over time (and with the motivation provided by the gas bill), I've gotten used to it being a little colder in the house and I wear sweatshirts a lot more. 

As for outdoors, the key for me is to always think to myself, "It's a little colder than it looks."  For some reason, when I look outside here in the UK, it always looks warmer than it is.  I do just fine by staying flexible with regard to outdoor clothing.  I've got sweatshirts, a couple of light jackets, and a couple of really warm jackets, and some combination thereof usually does the job.

Here in the midlands I tend to wear a fleece over a long sleeved top indoors in winter.  I find a 3-in-1 waterproof jacket is great for most of the year.  The outer shell is good for spring and summer rainy days, the fleece for dry but cool autumn days and both together is good for winter.

When I lived in Northern Idaho I got pretty stocked up on winter coats and jackets! I'm so glad I saved them all and brought them with me to England.

I always wear an under shirt or cami tank under my long sleeved wool tops and then a coat when ever I go out on freezing days. I can't stand the wind so I also wear some sort of hat and scarf if it's super cold out to keep my head warm.

On days where it's just a little chilly I can usually get away with just a hoody with a long sleeved top under.

It's not so much the cold you need to be concerned about - it's the wet!  Seconding waterproof (or water-resistant) shoes and good outer layers that can both keep you warm AND deal with rain.  When it's windy, umbrellas are simply useless.

I also wouldn't say it's "warm" inside in the UK.  My in-laws keep their house freezing (they don't turn the heat on and just use a small heater in the living room only) but I keep our house warm enough to walk around in a tee shirt.

As far as what to wear outside...I'm VERY cold-natured...this morning to walk my daughter to school in the freezing rain, I wore a tee shirt with a knit sweater and a windproof/waterproof lightweight jacket.  I had on a knit hat, scarf and gloves.  I was nice and toasty.  The difference is all in the jacket.  I have a huge, heavy, fur-lined suede coat that was always good enough in the US, but left me shivering here.  The lightweight (Regatta) jacket I have now is extremely thin but keeps me much warmer.  As someone else said, for me it's not necessarily the temperature but the wind...England is an island and sometimes I forget that...until I walk outside.

It is always a good idea to dress in layers anyway...because you don't know how warm/cold it will be where you are going.  That way you can peel as many layers off as you need to.  I always stick with three layers but what those layers are varies according to the weather (tank top on warmer days, long sleeve tee shirt on colder days, etc).  Sometimes the layers I wear are bulky so I bought my jacket a size to big so that I could fit my bulky sweaters on underneath it.  I do have a lot of girlie jackets (a pink fitted peacoat with pleated bottom, a black fitted trench coat, etc) but they aren't effective in keeping me warm right now...they'll be brought out in the spring when it's only cool as opposed to cold.

I'm from LA originally, and I would attract odd looks for wearing a sweater in the summer.

As for being cold indoors, it really depends on the house, how well sealed it is, how good the heating is, insulation, etc. My best friend lives in the exact style house as me, built in 1899, just a few doors down. Our house is usually very warm and I find hers cold in the winter. Oldies also tend to have their houses colder as heating is pretty expensive here, I think.

The upstairs of our house is quite cold in the winter, but we have an electric underblanket which my husband tolerates because he's lovely LOL I switch that on for 30 minutes or so just to warm the bed through and then I'm fine all night.

You won't need thermals for day to day use, but they might be an idea if you spend long periods out doors in Jan/Feb.

Remember, it's much colder out of town and up north than it is in London.

As Aless says, it's the damp you need to worry about, especially coming from the desert. It gets into your bones and once you get damp-cold, it's hard to get warm.

If it's cold and frosty, then it's dry and it's easier to stay warm. If it's drizzly or misty or damp, you get cold without it actually being that cold outside.

I find that warm socks, boots, jeans, long sleeves and my North Face down jacket are enough for me for outdoors.

Indoors, if it's chilly, 2 thin layers on top, tracksuit bottoms and socks keeps me pretty warm.

...England is an island and sometimes I forget that...

Just to be a wee bit pedantic, it's the UK or Great Britain that's the island...not England!

I would bring a lot of layers. Clothes are generally more expensive in the UK so I'd buy them in the US if I could.  As has been said earlier, you will find varying degrees of heat in people's homes and in offices, restaurants, shops, etc.  So you just need to be ready for anything!

The difference is all in the jacket.  I have a huge, heavy, fur-lined suede coat that was always good enough in the US, but left me shivering here.  The lightweight (Regatta) jacket I have now is extremely thin but keeps me much warmer.  As someone else said, for me it's not necessarily the temperature but the wind...England is an island and sometimes I forget that...until I walk outside.

It is always a good idea to dress in layers anyway...because you don't know how warm/cold it will be where you are going.  That way you can peel as many layers off as you need to.

I totally agree with this! I came from Florida to Reading. Though that's in the southern part of the UK and not terribly cold, it was a bit of a shock for me. The "sweaters" and coat I brought from FL were useless. Great excuse for new clothes! 

Another thing I found invaluable was scarves! I'd never really worn any before since I hadn't lived in a northern US climate and I didn't realize how useful they are. Besides being very fashionable  , they really make a difference by blocking wind from the neck opening of your jacket. Even in a restaurant or someplace where you don't need your coat, just keeping the scarf on will keep a chill away.

England is an island and sometimes I forget that...until I walk outside.

Ahem, England is part of an island.  

I found the damp/humidity is what really affected me. If it was cold and damp and I wasn't doing anything, I'd need lots of layers. But if I exerted the least bit of exercise (walking in town, biking) I'd get hot and very sweaty very fast from the humidity. Layers are key.