How to pack for Cotswolds in June?

I’m afraid that Britain’s weather is extremely unpredictable. Already this May over the last couple of weeks we’ve have everything from 28 Celsius to 12 Celsius. Last night there was a touch of frost for many of us.

So bring summer clothes but with some thin warm layers (or buy them here). A lightweight waterproof jacket or coat should be fine - easier to pack in a backpack.

What are you planning to do here? If you’re planning to hike on public footpaths or country lanes, be aware that public footpaths may just be unpaved tracks down the side of fields so if it does rain it’ll be muddy. I’d be wearing sturdy walking shoes or lightweight hiking boots to avoid turning an ankle climbing over stiles. However if you’re mostly walking within villages instead of public footpaths through the countryside, then good hiking shoes rather than boots would be fine. I’d also have some sandals in case of hot weather.

Shorts aren’t as widely worn in the UK as the US (and if you’re country walking, think about stinging nettles and brambles...) but I imagine they will take up very little room in your suitcase. How about those hiking trousers that unzip and turn into shorts?

But three main points: average temperatures mean just that, and you could have everything from wet and chilly to hot sunshine. Thin layers that you can take off, stuff in a backpack or tie around your waist are the way to go. And we have clothes shops here in the UK if you do bring the wrong thing.

I don't pay much attention to average temperatures, because the range around that figure can be extremely wide. I suggest going to wunderground.com, entering the name of your base town, then choosing History, Monthly and June 2017. Scroll down and look at the day-by-day actual temperatures for your travel period. Repeat for June 2016, June 2015, etc. That will give you a much better idea of what you'll actually experience.

My guess is that your odds of needing shorts are quite low, but I'm cold-natured and a weather pessimist.

I guess it's what you're used to, so 66 and dry sounds ideal to me! I'd expect it to be a few degrees north of that for the end of June. Humidity is not usually an issue.. You need to be prepared for it to be 80+ though as well as 65 and rain. My advice since planes tend to be cool, wear all your warmer clothes on the plane and pack you shorts and smaller summer items. Walking shoes not boots for the plane and sandles in your bag. May is currently looking pretty dry so we will be due some rain, although last year both June and May were lovely and the down pours started the day the kids broke up from school 21st July!

Does it get humid and buggy like New England?

No, never.

I might be slightly biased but a perfect English summer day cannot be beaten. Sunny, blue skies, mid 20's, not too hot, no humidity, no bugs (apart from a few errant wasps), glorious countryside and a pint or two in a pub garden. Perfectly reasonable to expect in late June although equally as reasonable to expect gloomy dreariness as well.

"Should I even bother packing shorts"
I do a lot of walking in the countryside but would never wear shorts due to the risk of picking up a few ticks, especially around sheep.

June weather -
https://weatherspark.com/m/41628/6/Average-Weather-in-June-in-Stow-on-the-Wold-United-Kingdom

36 Hours in the Cotswolds -
https://www.nytimes.com/2018/05/17/travel/what-to-do-in-the-cotswolds-england.html

I wouldn’t bother looking at average temperatures and weather for this year, as so far, no month has followed the usual pattern! We have had more snow this winter than the past 10 years combined, one day in April, the equivalent of a month’s rain fell in less than a day and 2 weeks ago, we had maximum daytime temperatures ranging from 5.5 to 28 degrees within 5 days of each other. This week is much windier than normal and it’s a cold wind.

Hopefully, the weather will be more settled by late June, so your temperatures should be in the 17-22 degree range. You may experience some showers, but you would be unlucky if you had wall to wall rain. Rural footpaths could get muddy, but you will be OK if you stick to pavements.

Use a British website such as bbc.co.uk to check the weather just before you leave to decide what to pack, such as if you will need a second pair of waterproof shoes for walking or sandals. Unless we get a heatwave, most Brits wear trousers, not shorts.

I took a moderately light rain jacket (probably from REI), and wore hiking pants most of the time. We did a walk to/from Bath with 3 nights in between, in late June a few years ago. We were rained on quite a bit the first few days, but I don't recall it being really cold, to the point of needing a warmer jacket. Dress in layers with a light rain jacket and you should be fine.

As others have noted, "averge" is just that. Expect that half your days may be hotter than the reported average high and half may be cooler. And if you are there for a week or more you can almost guarantee haveing a wet day. What you "need" will be highly dependent on you activities.

During one of my walking holiday in the Lake District the morning weather forecast called for generally fair weather with a slight possibility of afternoon thunderstorms. Needless to say, the afternoon thunderstorm becase a 100% probability storm and at one point we were walking down a country road in calf deep water. Waterproof anything didn't really work but my drybag kept camara safe.

https://www.metoffice.gov.uk/climate/uk/regional-climates

The UK is well known for the variability of its weather - from day to
day, season to season, year to year and place to place. Its position
in the mid-latitude westerly wind belt on the edge of the Atlantic
Ocean with its relatively warm waters, yet close to the continental
influences of mainland Europe, plays a major role in this. Changes in
topography and land use over relatively short distances, together with
a long coastline and numerous islands, all add to the variety of
weather.

Don't forget that the average high temperature is not the average for the entire day; it's the average you might expect at the warmest time of the day if every day of your trip is dead average. If you start hiking at 8 AM, it will be nowhere near the average high temp unless you're in the midst of a heat wave.