Fall in London

Either but I’d recommend going before British Summer Time ends (October 25 this year). October 25 is also the start of fall half term (school vacation) this year.

Yes, September. More likely to get the last vestiges of summer with the weather and the days are longer.

I personally think late October when the leaves are starting to change is a stunning time to be in London. I always do a lot of walking in parks and on the Thames Path in west London at that time of year. In recent years we’ve had some September heat waves that can be unpleasant.

I would definitely say September- it can still be somewhat nice weather here. Once we get into October it gets darker and rainier- October and November are my least favourite months here, tho on occasion the nice weather sticks around into October.

September and May are our favorite times to visit London, which we do almost yearly. September generally has fine weather, and the whole month has a festival celebrating the river Thames, with special events and programs. Not all have been credited yet, but you can keep an eye on their website:

https://thamesfestivaltrust.org/

I'm convinced the leaves turning on the trees are getting later and later every year. I'm pretty sure we were well into November last year and there was still colour. It's a big contrast when you go up to Scotland and the trees are all bare.

For sure that is true Gerry - I’m into photography and have a good record of prior years as a result. November is definitely the peak time. But there will be some trees starting to turn by the second half October. For example that is when the lime trees lining the Broad Walk in Regent’s Park turn orange, which is very beautiful and dramatic. I realise I am in the minority here, but I think October is beautiful in London.

September, obviously. Better chance of decent weather and lighter nights. I don’t think many people go to London to look at trees. Leaves them all for you Margaret!

Which month do you prefer and why?

To me it's six one way, half dozen the other. Seasonal changes, sunrise/set, or weather is the least of my concerns or considerations, and the difference between September & October are pretty negligible and insignificant. I'd be looking at schedules for festivals, cultural events, special museum exhibitions and the like, to influence my selection.

My last three trips to the UK were --
Last week February first week March
Last week October first week November
First half of October.

This October I will be splitting between Prague and London.

In my personal experience, there is a pretty big difference between September and October here- the start of September is still summer, there's 13.5 hours of daylight a day, you can sit outside with a pint, etc. By the end of October we are down to less than 10 hours of daylight a day and we'd be starting to put the heating on. October is also our wettest month. I suppose if you mostly want to do indoor activities it doesn't make a huge difference but if you want to spend more time outdoors I would definitely say September.

More info on monthly temperature and rainfall averages here: https://www.holiday-weather.com/london/averages/