Tips on avoiding crowds on weekend in London

Several years ago we were there on a Sunday and were able to walk from Buckingham Palace to Trafalgar Square on The Mall without traffic. Not sure if they still do this or not but on this Sunday, it was a pedestrian only street and it was amazing!!! So if they still close that street down on a Sunday, I would highly recommend doing that!!

The British Museum tends to be more crowded on weekends and Fridays, as well as on rainy days. I don't know what other sights might be similarly affected on weekends--maybe the Tower of London and the London Eye?

This is not an exact answer to your question but maybe it will be helpful. I was in London in late May last year for the Chelsea Flower Show and the only time I found it excessively crowded was on Saturday at Borough Market and around Trafalgar Square. For the big sights I try to book mornings soon after opening.

Charles, you're correct, The Mall is a pedestrian zone on Sundays and Bank Holidays.

My guess is that the main attractions, I.e., Tower of London, Westminster Abbey, Churchill War room, etc., will be busy. If you know when you intend on visiting them, buy your tickets early to avoid the lines and wait to get it.

trivia - in North America the word mall - like a shopping mall - is pronounced usually as mawl, a like in maw for mother. The road in London is pronounced mal - a like in cat, a short syllable, not drawn out. And it is The Mall

When in Spring? If it is May you have to consider the local public holidays on the 6th and 27th, plus Ascension Day on 9th May & Whit Monday on 20 May, as although neither of these are holidays in Britain they are in a number of other countries in Europe which increases those on short breaks to London..

The UK may not have a Bank Holiday as such for Whit Monday, but the reason we have two Public Holidays in May is that the origin of the late May Holiday is as Whit Monday. The date was only fixed as the 4th Monday in May in 1971- before then it was true Whit Monday, being 50 days after Easter Day.
In the north west of England, where I am from, there were (and still are) Whit walks that day. Those still coincide with open air Brass Band Contests- a big event in local life in parts of Lancashire and Cheshire (mainly now within Greater Manchester- especially my home borough of Tameside).

We will be there April 30th through May 7th. So it looks like we are going to hit May 6th holiday

You are visiting a very popular tourist city. Avoiding crowds will take research and planning. Are you a museum person? Prefer parks? Are street markets a must? Shopping? Foodie? Appreciate theatre?

Have you ever been there?

Planning is what I am trying to figure. I have been to London before, but it is the first time for my daughter.
So we would like to do "the great hits (Tower, British Museum, Westminster, etc.)" and I am just trying to understand if everything will be packed on that long weekend of May 6th, or if there are more and less crowded attractions on the weekend.
As an example Would the National Gallery or Imperial War Museum still be easy to get into?
What about taking a day trip to Bath for instance? Doable on Sunday or would be crazy packed?

I haven't been in London over the May holidays for decades, but I've spent a lot of time there in late August and September in the last ten years, including a bunch of trips to the National Gallery and the Imperial War Museum. I've never found those museums crowded to the point of affecting one's ability to move through them, unlike the British Museum, the Churchill War Rooms and Sir John Soane's Museum. It's not unheard of for a generally uncrowded, large art museum like the National Gallery to have clusters of people standing in front of a few very famous pictures, so I can't promise you'll be able to walk right up to Van Gogh's "Sunflowers" the instant you reach that room, but I wouldn't worry about going to the National Gallery on a holiday weekend.