Hire a local Village Hall / Community Centre - with an enclosed outside space is ideal. If the weather is really hot, consider putting up one of those dead simple and cheapo Marquees... to provide a bit of well needed shade. This advice is, of course, 'rich' as i was the only person today who managed to badly sunburn themselves.
And ask a few families to all chip in with the Hall cost and with the activities.
It might sound strange but you don't want 'too many' families as it can get a little bit manic and hectic. We do this every week and we have just 4 families with 8 children bewteen us. they are quite.... erm,,,,, LOUD! so we feel 8 children is enough (let alone the parents!)
I took a tray of pre-baked cakes for all the children to join and and decorate. Take some food colouring, a few packets of sweets and raisins, icing sugar, spoons - all that jazz - and that is snacking sorted.
If there is an adult who says they are not 'crafty' (is there such a thing?) then put them in charge of bringing all tea / coffee / drinks and milk to sustain the adults and children.
Then you set up several diffrent tables with the different activities on... The children can dip in and out of activities and bewteen playing as they want to. Each adult can bring something different to do. And that way, ideas and cost are spread pretty evenly.
Today, we decorated cakes.
And we did Marble Inking! We set up a long washing line to hang up our pictures. This was one of the major advantages to the gorgeous weather and crafting outside.
Somebody bought a big box of toys - somebody bought a big tub of Dressing-Up clothes - and I painted the Children's Faces as Dalmations and Pussy Cats....
Not that i'm telling you how to parent / play with your brood - heaven forbid! But this Weekly Play Club keeps our hard working group of Mums, a little bit saner. And it occured to me, if other parents booked a hall space in the Summer Hols, they could experience the fun we have? And it is surprising the skills and activities other parents have hidden.