It's official: it's no longer possible to use the weather to positively identify the season. If you went by what we've been experiencing in recent weeks, you'd probably, quite rightly, decide this was October. Your best bet in determining the time of the year, then, is by counting the number of open air shows that have kicked off in the UK, desperately and heroically contending with the non-stop downpours. Among the London offerings outside is the annual free production from Gods and Monsters at the Scoop theatre at City Hall and, I'll say this now: it's worth braving the high winds for.

Always ambitious in its vision, this year the company has taken on none other than Homer's The Odyssey, adapted from Samuel Butler's translation by Phil Willmott. And it is a bit of an odyssey, taking place over three hours, in three separate sections with breaks in-between, from 6pm to 9.45pm. It's not necessary to watch all three in one evening, however, and if you're rained off, you can come and catch the parts you missed another day.

In past years, the company has tried too hard to stage a complicated story, embellishing it with puppetry, poofs of smoke and the occasional visually arresting spectacle, which never really does the team many favours. It's hard to fill this amphitheatre space, especially when you're on a shoestring, and it can be especially hard to make even the basic special effects look convincing.

So it's great that this year the show has been pared right back, focusing purely on the script and the actors, in a neat, engaging storytelling mission. The main set – a map of ancient Greece on lots of different levels – is used well, re-inventing what is a fairly static set up in almost every scene. Penn O'Gara's costume designs are also ingenious, and enable a small cast to play a vast number of characters with ease.

The ensemble cast this year are very strong too, with PK Taylor an excellent Soothsayer, Lawrence Boothman a very funny Eurylochos the Cynic alongside goofy wing-man Alex Porter as Philotios, while Adrian Decosta manages to swing from Argos the dog to Telemachus beautifully. The whole cast, though, are great and between their focus and the script, they make an excellent family-friendly tribute to one of the most engrossing of stories. It's well worth bringing your waterpoofs, layers and a cushion or two to experience this adventure.

The Odyssey runs at the Scoop until 3 September.