We think London is at its best in the last two weeks of September. But there's actually plenty to do and see the year round. Weather is likely to be a major factor and it often surprises visitors to find that August is quite a wet month.
For a list of military ceremonial events (there are a surprising number, not just changing of the guard) see the Army's Website. Actually it can be more fun to attend a rehearsal of an event such as 'Trooping of the Colour' consult the list before you come..
For the official public events calendar click HERE
London Calendar:
January: Often a pleasant month - not too cold, and not too wet. The very end of the month sees Atlantic gales blowing in. The Sales are on and everyone is shopping crazy. The theatres & concert halls are getting back to normal after the Christmas rush: good ticket availability. On the 1st a New-York style parade through the centre of town.
February: Unpleasant. Not cold - but dull with low cloud and rain. Those in the know are off skiing. Little to recommend the month apart from low hotel prices. Theatre and music often quite good by compensation. Chinese new year celebrations (lunar, so shifts) in Soho - nice day out, if crowded. At end of month (depends on the lunar feast of Easter) there can be a half term holiday week for schoolchildren when things get chaotic - avoid.
March: like February, only less so. Unsettled weather: some sun but also wet and windy. Where there's an early Easter things get better: school half-term holidays can liven things up (movable feast). Oxford/Cambridge boat race usually last weekend. British Summer time begins end of March.
April: weather getting better though often wet and windy. Some optimists hold 'Spring festivals' of theatre, music etc. London Marathon. Watch out for Easter. Bank (ie public) Holiday 1st April.
May: most brits vainly hope summer is upon them in May, and are cruelly disappointed. Although it is getting warmer and there is more sunshine, showers betray the foolhardy. Extremely hard to predict the weather. May day is celebrated in Oxford and sometimes in London (eg Hampstead, Greenwich) with Morris-dancing and other festive treats. Football cup-final (usually). Coin Street Festival on South Bank. Chelsea Flower show. First Monday is a bank holiday.
June: Generally dry and sunny but can still upset as brief storms blow in off the Atlantic. Some venues like the Barbican can be beginning their Summer shut-down. Pub-theatres and other small venues begin their pre-Edinburgh run of comedy and short plays. Horse guards - trooping of the colour and beating the retreat rehearsals - first week. Royal Academy summer exhibition of dreadful painting. City of London Festival (good) of theatre and music, Covent Garden Festival. Wimbledon tennis championships. The Derby and Ascot horseracing.
July: It's summer and warm enough to wear just a tee shirt - usually. Don't forget that umbrella though as the storms are now coming in from another direction. Music drying up in preparation for the Proms. Hampton Court flower show (this one's actually for gardeners)
August: Dearth of theatre as most companies are up in Edinburgh for the festival. Proms are on every night suffocating other music venues. Countryside in bloom. Lots of tourists - hotel prices soar. Notting Hill carnival last weekend in August (avoid). Last Monday usually a bank holiday is a bank holiday.
September: The best time to visit London. Warm, usually dry, especially the latter half. Open House Day (actually a weekend) when you can visit buildings normally closed to the public. Theatre back from Edinburgh with a host of new shows. Proms ends with its last night and the new music. Opera and theatre season begins. Pleasant slightly misty evenings. Seafood festival in Hay's Galleria. Soho Jazz festival (good).
October: Like September but shorter days and less buzz. Or it can rain. Unpredictable. That Indian Summer is trying to work its way in but has to push out a lot of rainclouds to do so. Theatre and music good. In 2001 there were many, many days of warm, sunny weather, but one month's rain fell in one day, screwing up the rainfall averages and causing flooding in central and eastern Britain. British Summer time ends end of the month - expect a glum week as the nights draw in.
November: truely Autumnal: the battle is on between the fading Indian summer and the next lot of wintery rainclouds. The 5th is Guy Fawkes night when Catholics are burned on bonfires across England (actually only straw dummies) and fireworks are let off. Lord Mayor's show.
December: Chilly but often dry. Shopping frenzy pre-christmas. Most businesses do most of their trade in this month. Pretty lights in streets. Lots of very drunken office parties in latter half. Christmas week is dead. New Year's eve celebrations in Trafalgar Square. If able book the new year away, either out of London in Norfolk of the northwest of Scotland, or in North Norfolk - or on a mountain with good skiing.