The weather--gotta ask this!!

You should always prepare for rain in the UK.

It might rain, it might not.

Why are you concerned?

When you are finalizing you packing for the trip, check the online weather sites for what the predict it will be while you are there. While not perfect, this should provide you with a rough guideline as to if you should take t-shirts, flip flops, and shorts or your Atlantic fishing trawler rain gear. Or whatever in between.

I always get by with a comfortable pair of boat shoes that don't mind getting wet and a trusty compact umbrella that at least keeps my head dry unless the wind gets to whipping.

My solution during a 10-day stay in London last September was to carry either a hooded rain jacket or a folding umbrella (sometimes both) around with me every day. The one time I head out with nothing, I looked up at the sky as I walked out the door (facing in the opposite direction from my window) and turned around and retrieved my raingear. There was never enough rain to affect my day; I just had to make room in my purse for the jacket/umbrella. I also has a light fleece jacket to serve as my warm layer, and I wore it most days, if not all.

I think London is warmer in June now, on average, than it used to be back in the 1970s and early 1980s; I remember freezing back then--but I wasn't traveling with a fleece jacket, either.

Why don't you take a look at the actual, day-by-day temperatures and precipitation reports for the last few years on Wunderground.com? Choose History - Monthly and use the pull-down boxes to select June for several recent years. I've linked to June 2017.

Who knows what June will bring?

So far this year, I have been to the Canary Islands, where they have had their worst winter for 40 years (cold and wet) and I am currently away in Portugal, where they have had one of the wettest March months on record.

In the south of the UK where I live, we have had more snow since Christmas than all the other 17 years I have lived there combined!

Despite what most think, London gets relatively little rain compared to say Scotland or western counties. In June, usually if there is any rain, it will be a light shower, but these days “usually” may or may not be applicable! Bring a lightweight waterproof with a detachable hood just in case - far more useful in crowds than an umbrella.

Buy an umbrella, a wonderful invention. There is a very special shop in London where all the best people buy their umbrellas but one from Marks and Spencers will do the job as well. Think of it as an adventure.

Weather? Temperatures? Precipitation days?
Look the city up in Wikipedia.

My first trip to Europe was a week in England and a week in France (end of May, beginning of June). We didn't have a drop of rain in England, only one cloudy day and the rest was sunny/partly cloudy and mild. We arrived in France and it started raining and rained off and on for four days - not hard rain just dreary and drizzly. So, you just never know even a few days in advance, let alone months in advance. Just be prepared for some rain - light rain jacket, umbrella or rain hat, extra pair of shoes, and you should be fine.

Honestly if it rains you won’t melt and as someone who is a CA native I embrace the difference in weather. SUNNY weather 365 days a year bores me.

I always find if I carry an umbrella no rain. If I don't carry an umbrella then there is rain. And a year ago when I left my trusty umbrella in the apartment I was renting in Rome to go to Galleria Borghese when we emerged - pouring rain. We followed a crowd and traveled underground and emerged at the Spanish Steps, got turned around and went the wrong direction (still pouring rain) finally broke down and bought a 5 Euro umbrella, the rain stopped 5 minutes later and I had a lovely orange umbrella that stayed in Rome for the next person who rented the room. Always bring 2 pairs of shoes so if one is soaked you can wear the other pair.

" We arrived in France and it started raining and rained off and on for four days "

Yes.......The French usually keep very quiet about that, of course it only rains in England, everyone knows that.:-)

On average more rain falls in Paris than London in 11 out of 12 months in the year, November being the exception.

I always bring a waterproof jacket with a hood - then no worries. I'm from California too, and it's not a problem.

Bring a waterproof rain jacket with a hood and you are good to go!

By all means take a light waterproof rain jacket with hood and waterproof shoes. But also have flexible plans for each day - outside activities and inside options if the weather takes a turn for the worse. With London's many museums, there are plenty of options for walking indoors and often the rain will just be a shower that is over quickly. Just enough time to stop in a pub for a drink or have a cup of tea or coffee at a cafe. Prepare for the possibility but don't let it spoil your trip!

cloudy overcast, OK, but rain I'm concerned about.

Why? What's the problem with rain? England is verdant & lovely for a reason!