September is one of the best months to visit London: the weather is usually still mild, the school holidays are over, and the city fills its calendar with free events such as the Open House festival and the Totally Thames river festival. It is also the last chance to see some summer-only sights, including the State Rooms of Buckingham Palace.
In early September British children go back to school, and the difference is noticeable within days. Museums are calmer on weekdays, the queues at the big attractions shrink, and the city starts to feel like it belongs to Londoners again. The evenings are shorter than in August but still light enough for a walk by the river after dinner.
Below we cover what September weather is like, the events that fall in the month, what closes as the summer season ends and how to pack. Dates are given only where the organisers have announced them.
September in numbers
- Average high / low
- 20.2°C / 11.6°C (Met Office, Heathrow, 1991-2020)
- Rainfall
- 49.6 mm on about 8 days with 1 mm or more
- Sunshine
- About 157 hours, roughly 5 hours a day
- Bank holidays
- None in September
- Schools
- Back from the first week (in Lambeth, 2 September 2026 and 1 September 2027)
- Free festivals
- Open House (2026: 12-20 September) and Totally Thames (all month)
The weather: summer's quieter second act
The Met Office averages for Heathrow give a daily high of 20.2°C in September and a low of 11.6°C. In practice the first half of the month often feels like a gentle continuation of summer, while the last week or two bring cooler mornings and the first real hint of autumn. Warm spells of 25°C or more are possible, but so are grey, breezy days.
September is on average one of the drier months, with 49.6 mm of rain and about eight days with at least a millimetre. That compares well with October, which is noticeably wetter. You get about 157 hours of sunshine across the month, less than in August but still enough for long days outdoors.
For walkers this is ideal weather. A riverside route along the Thames from Westminster to Tower Bridge is pleasant rather than tiring, and our guide to getting around London on foot shows how often walking beats the Tube over short distances in the centre.
Photo: AndyScott · CC BY-SA 4.0 · Wikimedia Commons · resized
Open House: a week inside buildings that are usually closed
The Open House Festival is one of London's great free events. For about a week, private homes, offices, government buildings, engineering sites and architects' own houses open their doors to the public, usually with volunteer guides. It is organised by the charity Open City.
The 2026 festival, the 35th edition, ran from 12 to 20 September. Entry is free. Many buildings are walk-in, but the most popular ones need a ticket, and you have to create a free account on the Open City website to book ticketed activities. The 2027 dates had not been announced when we checked, so watch the Open City festival page from the summer.
Book the famous Open House buildings the moment tickets appear. The best-known places are gone quickly, but the walk-in list is long, so you can still fill a free day without a single booking. Pick one area and walk between neighbouring buildings rather than crossing the city.
Totally Thames and the river in September
Totally Thames is a month-long festival of arts, talks, walks and river events along the Thames, run by the Thames Festival Trust. For 2026 the organisers say it runs "throughout the month of September" but have not published exact dates for every event, so check their programme for what is on during your stay. The old totallythames.org address now forwards to the Thames Festival Trust website.
The festival is spread out, so it works best combined with a walk along the South Bank or a crossing of several Thames bridges. Many events are free. September light is softer than in midsummer, which makes it a good month for river photographs.
Last chances before the summer season closes
Several things that define a London summer come to an end in September. It is worth knowing which, so you do not plan around something that has already closed.
- Buckingham Palace State Rooms: in 2026 the summer opening ended on 27 September. In September the palace was closed on Tuesdays and Wednesdays, open 9.30am with last admission at 4.30pm. Adult tickets cost £33.00 in advance or £37.00 on the day.
- BBC Proms: the 2026 season ended on 12 September with the Last Night of the Proms. Our Proms guide explains how the season works; 2027 dates are not yet out.
- Regent's Park Open Air Theatre: the 2026 season finished with a Live Music Week from 22 to 27 September.
- Serpentine Lido: the swimming season usually runs from June to mid-September.
- Kew Palace: the Historic Royal Palaces buildings at Kew close from 28 September 2026 until spring 2027. The gardens stay open.
If a visit to the palace is on your list, September weekdays other than Tuesday and Wednesday are usually less crowded than August.
Deer, gardens and the first autumn colour
September is when the red and fallow deer in Richmond Park begin their rut, the breeding season that runs until November. The stags roar, clash antlers and can be dangerous. The Royal Parks asks visitors to keep at least 50 metres from deer at all times, and at least 100 metres from an active male during the rut. Feeding deer is illegal, and dogs should be on a lead near them or walked elsewhere.
At Kew Gardens, September opening hours are 10am to 7pm, with last entry at 6pm. An adult ticket costs £25 online or £28 at the gate (peak period, 2 September to 31 October 2026). From 8 September 2026 there are "£10 Tuesdays", which make Kew one of the cheapest big days out of the month.
The Diana Memorial Playground in Kensington Gardens closes at 6.45pm in September, an hour earlier than in summer.
Ceremonies, art and football back in full swing
With the summer crowds gone, ceremonies such as the Changing of the Guard are easier to watch. In September 2026 the Guard Change at Buckingham Palace took place at 11am on Mondays, Wednesdays and Fridays, but not on every one of those days. Always check the Household Division's calendar the day before.
On Trafalgar Square, a new artwork went up on the Fourth Plinth on 10 September 2026: Lady in Blue by Tschabalala Self. It is free to see at any time.
Several galleries also open late on some evenings. Tate Modern holds regular Lates (one was held on 25 September 2026, 6pm to 10pm), and our overview of late openings at London museums lists the rest. Tate Modern itself is open until 9pm on Fridays and Saturdays.
The football season is also under way. Six London clubs play in the Premier League in 2026-27: Arsenal, Brentford, Chelsea, Crystal Palace, Fulham and Tottenham Hotspur. Our guide to Premier League tickets explains how visitors can get into a match.
Crowds, prices and when to book
September is often called the shoulder season: busier than winter, calmer than high summer. The first weekend can still feel like August, because some European schools return later than British ones, but weekdays from the second week onwards are noticeably quieter at the museums and the Tower of London.
The month is not empty, though. Business travel picks up again after the summer break, so do not expect bargain hotel rates. Book as early as you would in summer and compare a few areas. Our article on the best time to visit London weighs September against spring and early summer.
Book day trips before the price bands change on 28 September. Stonehenge moves from peak weekend prices to its cheaper autumn bands on 28 September 2026: weekdays become off-peak and weekends standard. If your dates are flexible, a visit at the end of the month costs less. See our Stonehenge day trip guide for the prices.
A September packing list
Layers are the answer in September. A typical day might start at 12°C and reach 20°C by mid-afternoon, then cool quickly after sunset. Bring:
- T-shirts or light tops, plus a jumper or fleece for the evening;
- a light waterproof jacket that packs small;
- comfortable shoes for Open House days, when you may walk several kilometres;
- sunglasses and a little sunscreen for the warmer days early in the month;
- a phone with a charged battery and headphones, as some attractions now offer free audio guides on your own phone.
Many of the best things this month cost nothing. Our list of free things to do in London fits neatly around a September trip, and if you are still deciding on dates, our August guide shows what you gain and lose by coming a few weeks earlier.
Frequently asked questions
Is September a good month to visit London?
Yes. The average high is about 20°C, it is one of the drier months, and the attractions are calmer once British schools return in the first week. You also get free festivals such as Open House and Totally Thames.
When is Open House London?
The 2026 Open House Festival ran from 12 to 20 September. The 2027 dates had not been announced at the time of writing. The festival is free, but popular buildings need a free ticket booked through an Open City account.
Can I still visit Buckingham Palace in September?
Usually, yes. In 2026 the State Rooms were open until 27 September, closed on Tuesdays and Wednesdays in September. After the summer opening, only small, expensive guided tours on selected dates are offered, so September is the last easy chance.
What should I wear in London in September?
Dress in layers: a T-shirt for the afternoon, a jumper or light jacket for the morning and evening, and a waterproof for showers. Comfortable walking shoes are essential, especially if you plan to follow the Open House trail.
Is London cheaper in September than in August?
Attractions are generally less crowded, and some day trips move to cheaper price bands at the end of the month. Hotels stay in demand because of business travel, so book early and compare areas rather than expecting large discounts.
Sources
- Met Office - Heathrow climate averages 1991-2020 (checked September 2026)
- Open City - Open House Festival (checked September 2026)
- Thames Festival Trust - Totally Thames (checked September 2026)
- Royal Collection Trust - Buckingham Palace (checked September 2026)
- The Royal Parks - Deer safety advice (checked September 2026)
- Royal Botanic Gardens, Kew - Tickets (checked September 2026)
- Mayor of London - Lady in Blue unveiled on the Fourth Plinth (checked September 2026)
- Lambeth Council - School term dates 2026 to 2027 (checked September 2026)