Dressing for May in Lake District, Cotswolds, London (male)

All right Mike, your first lesson in English. You are talking about trousers, not pants. Pants are underwear. What fun you're going to have!
Trying to chase English weather can drive you truly insane. You may have days in the 30's (F), and days in the 70's (F). It may snow. It WILL rain. Do take a warm wool sweater and a really good breathable waterproof jacket. You sound like a hiker, so you probably have these items already. I don't do rain trousers, so I take along a few zippy sandwich bags for passport and wallet. Always helpful when you are soaked from the thigh down.
As to the number of pairs of trousers and shirts you're going to need, I have no idea. It really depends on your personal grunge factor. I personally load up on underwear and socks and minimize the outerwear. You might want to try the Oxfam Shuffle. Pop into a charity shop for two or three shirts when you arrive (and yes, you may have to wear them with the sleeves rolled up). The Brits are big on charity shops. Just toss them after you've worn them for a few days, or better still, re-donate at the next shop you see. If you are going to just carry on for the return trip, please remember that you will have lots more stuff then when you began, so throw away clothing is a plus.
When you get out to the Lakes, you will find more B&B's that are willing to do a load of clothes for you (normally for a fee). They cater to walkers (hikers) out there, but it's worth asking when you make a B&B reservation anywhere. Laundry privileges are more important than a "lovely, warming, cup of tea upon arrival."

Have a great time!
Curt

My husband and I are going to London and York in May. We are only taking our carry on and a back pack. I will pack three pants and wear one of course. I will take an unlined rain coat with hood. I will take a zip up fleece and 4-5 long sleeve T shirts to wear under the fleece on colder days. And then throw in 3-4 medium weight tops. The rain coat is packable, so then I will wear a lighter blazer on the plane for the no rain days. We also save older underwear and toss as we go to lighten the load by the end of the trip. My husband will do about the same with menswear. He usually only takes one pair of shoes because of their size. I can pack a smaller loafer type shoe to have two pairs. I take small size toothpaste and deodorants that we can toss the containers as we go. And as Rick always says you can pretty much buy anything you need in Europe as you go! Have a great time. You will be so happy you are not carry too much stuff.

England never gets cold enough in the winter where a fleece and rain jacket over a shirt is not sufficient.

England never gets warm or dry enough in the summer to where you don't need one or the other.

Work from there.

Thanks for everyone's replies! Great stuff for me to ponder here.

I also highly recommend asking about laundry service when you book a B&B. Having laundry done while out sightseeing is a service well worth the cost to me because it saves a ton of time and allows me to pack much lighter.

Cotton or blend turtlenecks or polos under light wool sweaters or zipneck or pullover fleece tops will work for both sexes. These can rollup and come out without wrinkles...no ironing and usually forgiving in fit. I wouldn't wear jeans myself because of their weight. I have been in the UK in April (Snow flurries), May (Rain), September (Nice, Rain) October (Heavy Rain). So you will love having waterproof or weather resistant foot wear...you don't need boots unless you are mountain climbing...just nice oxfords with a rubber sole. Ladies can bring slipons for going to theatre or dinner at a fancy place.

Thanks, everyone!

Footware seems to come last, yet shoes are both bulky and heavy in a carry-on. Given the walking you hope to do, I suggest getting a good pair of all-purpose athletic shoes (I use New Balance because of the fit). Look for a model that is all-black with a discreet logo. They can pass for more formal shoes in restaurants etc. Wear them on the airplane. Pack a light pair as backup, particularly if the walking shoes get wet, quite probable at that time of year in both town and country.

welcome brown,

Weather is RELATIVE.

If you ever go to Hawaii and its in the 70s, you will see the locals bundled up in parkas. For them its cold.

So depending on where you are from and the weather where you are going, it may not be cold to you.

you can google average daily temps for areas and time of year if you like and assume mother nature will follow it. Other than that, be prepared.

happy trails.

I will tell you what my husband takes. We go for 16 days at a time and our trips include everything from serious hiking in the mountains to city treks to fine dining. He packs all he needs in a carryon size bag ( and so do I). For shirts, he takes 2or 3 of the shirts he practically lives in when not working: fine Merino crew neck shirts by Icebreaker. The one called Tech Lite comes in long and short sleeves. The long-sleeve is on sale for $59 at Backcountry.com.

http://www.backcountry.com/icebreaker-superfine-150-ls-tech-t-lite-shirt-long-sleeve-mens?ti=UExQIEJyYW5kOk1lblwncyBTaGlydHM6MTozOjEwMDAwMDA2Ml9iY3NDYXQxMTAwMDc1

This is very fine, lightweight, totally non-scratchy Merino wool from New Zealand. It is machine washable and line dries in hours in a dry climate, overnight otherwise. He likes the crew neck but they make other styles like quarter zip, v-neck, and polo. So does another company called Ibex. You can look for them at deep discount price son Sierratradingpost.com too.

He used to wear the polyester tech clothing like Underarmour or Patagonia, but I made home switch to wool to avoid the stinky factor. The polyester shirts have to be washed after each wearing, and the wool ones do not.

He also takes one button-down Brooks Bros no-iron shirt to wear with a tie ( or not) when we go fancy.