Ten things to do with LittleHumans in London this September

September is when London gets its parks back. School is in, the crowds thin, and the small, volunteer-run things that never make the big lists have the city to themselves for a month: farm shows, a village fete, steam engines, boats. Ten moments worth building a day around, chosen for LittleHumans aged 0 to 7. Saturday 19 September is the busiest day of the month, so pick one.

1. Diana Memorial Playground, Kensington Gardens

Back since 5 August after a £3m renewal, and September is the month to go: term-time weekdays are the quietest it will be all year. A 17-metre galleon with crow's nests and a tunnel slide, a three-tower treehouse, a crocodile water sculpture and a new corner for under-3s. Free, fenced, and no adult goes in without a child. The playground's own toilets and the water play are both off for now, so go prepared.

2. Tidefest, Strand-on-the-Green (6 September)

The riverside lane in Chiswick fills for a day of free children's activities, boat trips, paddleboarders to watch, a foreshore nature walk and a street party outside the pubs. Volunteer-run and properly local. Check the tide: at low water the foreshore opens up for wellies and pebbles.

3. Classic Boat Festival, St Katharine Docks (12 and 13 September)

Over 70 old boats fill the marina a minute's walk from Tower Bridge: steam tugs, Thames sailing barges and Dunkirk Little Ships, with a salute of horns at opening and closing and children's activities on the quay. Free. Come on the Saturday and you can also catch the Great River Race, 300 boats rowing from Millwall to Richmond, sweeping under Tower Bridge from around 1.15pm.

4. Autumn Crafternoon, Chelsea Physic Garden (13 September)

Sunday 11am to 1pm: bugs and birds made from twigs, conkers and acorns in London's oldest botanic garden, then the walled garden itself to wander. £10 to £15, booking needed. Check the age guide when you book; the crafts want steady hands.

5. London Harvest Festival, Mudchute (19 September)

Every city farm and community garden in London brings its animals and its best produce to Mudchute on the Isle of Dogs, 10am to 5pm. Livestock judging, a horticulture show, heritage crafts to try, and twenty farms in one park with Canary Wharf on the skyline. Entry and every activity free. No parking, so take the DLR to Mudchute or Crossharbour.

6. Steam gala, Ruislip Lido Railway (19 and 20 September)

The railway's engines out together on Britain's longest 12-inch line, circling a lake with a sandy beach and woods to walk. Under-3s ride free; a day rover is £10 for adults and £5 for children, and entry to the park costs nothing.

7. Polka Theatre reopens, and the Big Dreams Festival (from 9 September)

Wimbledon's children's theatre reopens on 9 September after summer building works, then throws a festival on 19 and 20 September made for the very smallest: a Family Rave for 0 to 4s, an After Party for under-2s, Multicolore for 18 months to 6, and Nick Sharratt drawing along with 3 to 7s. Book ahead; the small shows sell out.

8. Bermondsey Street Festival (19 September)

The street behind London Bridge closes to traffic, 10am to 5pm, for a free, volunteer-run village fete now in its 20th year. Music in Tanner Street Park, a Family Fun Hub, a dog show, independent stalls and street entertainers. Leathermarket Gardens, halfway along, is where to park the pram and let a small one loose.

9. Family Freestyle, Sadler's Wells East

Free dance sessions for 2 to 4 year olds and their grown-ups, every Thursday and the second Saturday of the month at 10am and 11am, led by professional dance artists in the new building on the Olympic Park. No booking: register at the welcome desk and come early, as places are limited. The park's playgrounds are outside the door afterwards.

10. Last weekends on the Brockwell Park Miniature Railway

The volunteer-run railway runs Saturdays and Sundays to the end of September, then Sundays only through October before closing for the year on 1 November. £1 a return for everyone, under-2s free, and the trains pull away from beside the playground.

Image credits: Mudchute Park and Farm by ClemRutter (CC BY-SA 4.0); St Katharine Docks and Sadler's Wells East by The wub (CC BY-SA 4.0), all via Wikimedia Commons.