Yes, it's September already. Then next month the clocks go back, then it's Fireworks Night and before you know where you are Christmas will be rolling round again. Never fear, London always puts on a last flurry of events and activities and happenings before the nights draw in, and we're all invited. Here's my weekend by weekend guide to free September delights.
All month
» Totally Thames (Sep 1-30): There was a time, not so long ago, when the Mayor's Thames Festival filled the South Bank and lit up the sky for one weekend in September. No more. Now we get a whole month of events, many of them ticketed, kicking off today with the arrival of a three-storey floating lantern by Tower Bridge. If you fancy a Lost Rivers walk or a talk by an expert, prepare to stump up, but there are also plenty of splendid freebies, if you don't run out of patience scrolling through the frustratingly over-tiled, impractically atomised programme.
» Lambeth Heritage Festival (Sep 1-30): Dozens of talks, walks and openings across the borough, notably featuring Lambeth Palace, Brixton Windmill and the River Effra (and a proper brochure to flick through, bliss).
Weekend 1: September 3/4
» London's Burning (Thu-Sun): A major series of events to commemorate the 350th anniversary of the Great Fire of London, including a Fire Garden outside Tate Modern (Fri-Sun), a domino-topple in the City (Sat, 6.30pm), underwater ballet in Broadgate (Thu-Sat) and the burning of a wooden city on a barge in the Thames (Sunday evening)
» The Great River Race (Sat, noon-3.30pm): 300 craft engage in a spectacular paddle up the Thames from Docklands to Richmond.
» Liberty Festival (Sat, 1-6): For National Paralympic Day, the annual deaf and disability arts extravaganza in Queen Elizabeth Olympic Park.
» Angel Canal Festival (Sun, 11-5): Waterside gaiety beside City Road Lock, now in its 30th year. Expect the Mayor of Islington to arrive by narrowboat.
» Horniman Carnival (Sun, 12-5.30): Brazilian-themed concerts, dance and colourful parades in the Gardens.
» Palmers Green Festival (Sun, 12-7): All the fun of music on the green, Salstricity and Britain's tallest mobile climbing wall (in Broomfield Park).
» Brentford Festival (Sun, from 12): Live tunes, stalls and a dog show, plus 18 ales via CAMRA, in Blondin Park W5.
Weekend 2: September 10/11
» Heritage Open Days (Thu-Sun): Hundreds of buildings that aren't usually open, are open. Most of them are outside London, but there are plenty open in Kingston (which is spending the weekend pretending it's in Surrey).
» St Katharine Docks Classic Boat Festival (Sat, Sun, 11.00-5.00): Annual gathering of small boats near Tower Bridge. Includes a visit by The Barnet Hill Lifeboat Crew Shanty Singers.
» Hidden River Festival (Sat, 10-6.30): In its fourth year, a music festival and family funday on the banks of the New River at Woodberry Down.
» Brazil Day (Sat, 12-7): Remember Rio and feast on all things Brazilian in Trafalgar Square.
» Hackney Carnival (Sun, 2-5): Not of Notting Hill proportions, but follow the feathers and sound systems from Ridley Road to the Town Hall (and back).
» Tour of Britain (Sun, 2.30-4.30pm): The final stage of this cross-country bike race is a lycra-tastic sprinty circuit heading in three directions out of Trafalgar Square. Ironically, the new East-West Cycle Superhighway means that the route no longer follows the Embankment.
» Kings Place Festival (Fri-Sun): Head to King's Cross for 100+ performances of spoken word, comedy, dance, jazz and classical music. Here's a list of the free events.
» Essex Architecture Weekend (Sat, Sun): OK, it's outside London, but there are many quirky 20th century buildings to explore in this one-off suburban celebration.
Weekend 3: September 17/18
» Open House London (Sat, Sun): The grand-daddy of architectural festivals, with hundreds of weird and wonderful buildings throwing open their doors across the capital. Alasdair's excellent summary list is here. Some of the really special events are fully booked, and you're now too late to sign up for the Downing Street raffle. However, today's the day to grab a ticket to modernist Highpoint (bookings from 9am), while the seven Crossrail building site tours go live this afternoon at 1pm. There'll be tons to see over the weekend, in fact far too much to choose from. Be there, or regret it for the subsequent 52 weeks.
» Great Gorilla Run (Sat, from 10.30): Dress up as a gorilla and run 7km to raise money for charity (or just come along and watch sweaty knackered apes).
» Bermondsey Street Festival (Sat, 11-6): A designery "village fête", plus dog show, plus food and stalls (with or without Zandra Rhodes).
» Thames Sailing Barge Parade (Sat, from 3.30): A one-off regatta of historic craft sets sail from Docklands to Tower Bridge and back. Followed by an Open Day at West India Dock on the Sunday.
» Sail Greenwich (Thu-Sun): The Royal Borough wants to flog you a cruise ticket, but alternatively watch the tall ships from the shore for free.
» London Design Festival (continues until next weekend): Hundreds of design-er events will be taking place across the capital, based in seven on-trend clusters. Having struggled through the programme online, I think the V&A looks your best bet.
» Estuary 2016 (Sat, Sun): Just outside the capital, the Shorelines Literature Festival takes over the heritage spaces at (and around) Tilbury Cruise Terminal.
Weekend 4: September 24/25
» Malaysian Night Market (Sat, noon-10): Food and dance (but mostly food) in Trafalgar Square. Followed on Sunday by the Japan Matsuri festival (12-8).
» Pearly Kings and Queens Harvest Festival (Sun, from 1pm): Cockney royalty circles the City from Guildhall Yard to St Mary-le-Bow.
» Deptford X (from Friday 25): Five emerging contemporary artists make merry in SE8.
» There must be something else on this weekend, surely.
(and sneaking into the first weekend of October)
» Thames Barrier Closure (Sun, 6.30-4.30): Annual all-day maintenance closure (peaking around high tide at 3pm). Come and see water piled up on one side only... while it's only a practice.
» Autumn Ambles (Sat, Sun): 42 free guided walks from Walk London... but no turning up on spec, you now have to book ahead.