As the nights draw in and we head deeper into autumn, small towns across the West Country are gearing up for a series of spectacular illuminated night-time carnivals. Although these processions draw crowds of up to 150,000 and have been held for some 400 years, they are little known outside the area. They may well be Somerset’s best-kept secret. Their gaudy but spectacular floats are adorned with up to 30,000 lightbulbs, and some are more than 100ft long, carrying their cargo of wild dancers and blaring music.

I grew up in Somerset and my first experience of the carnival came at the age of 10 when I unsuccessfully tried to join the masqueraders. My companion, a Shetland pony, quite rightly objected to the loud music and bright lights and my carnival queen dreams came to a halt.

Since then I remained largely ignorant of carnival developments until last autumn when I visited Shepton Mallet, a small, no-frills rural town near Bath. I was immediately pulled back into that world, watching surreal carnival legend Mike Daniels whizz past me on his mobility scooter dressed as a purple nun, followed by a couple festooned in LED lights and kitted out as a polar bear and the Arctic king. Then came a Waterloo tableau, featuring 30 skeletons lit up by UV and a fire-breathing dragon with 20 dancers attached to its moving body.

The most remarkable element of the carnivals is the dedication of the people involved. Daniels, the lurid purple nun, told me that in 27 years he has missed only one season – when he was recovering from a stroke. The carts and costumes are entirely self-funded so the carnival clubs must raise tens of thousands of pounds each year to develop ever-more-complicated and eye-catching carts.

The carnival processions take place in West Country towns in the two weeks after Guy Fawkes night and have been going since the gunpowder plot of 1605. That historic date, 5 November, was especially celebrated in protestant Bridgwater, where a local Jesuit priest was part of Guy Fawkes’s attempt to blow up parliament. Across the West Country, bonfires and the burning of tar barrels and Guy Fawkes effigies gave way to fireworks, theatre and processions.

Bridgwater is the first and largest of these Guy Fawkes carnivals and the only one where there is “squibbing” after the procession. Squibbers walk poles with exploding fireworks through the town, scattering the crowds at the front with burning embers. Those well versed in carnival-watching make sure they wear old coats and hats.

After Bridgwater, the two-hour-long procession tours seven towns including Burnham-on-Sea, North Petherton, Shepton Mallet, Wells and Glastonbury. By far the most charming place to see the carnival is Glastonbury, the last in the circuit, on 19 November, where the lights are reflected in the windows of the many crystal shops lining the sloping high street. Crowds line the streets for hours to secure a good view of the procession. The best way to enjoy the show is to arrive in the town before 5pm when the road closures start.

A sunset hike up to the legendary Tor to admire the ruins of 14th-century St Michael’s Tower as well as the remarkable views over the Somerset Levels will set you up for a meal in one of Glastonbury’s many pubs. The walk is a mile from the centre of town and a torch is useful coming back after sunset.

A visit to Somerset isn’t complete without trying a food and drink tour. Hidden treasures include the Somerset Cider Brandy Company at Burrow Hill, the Brown and Forrest smokery in Hambridge for its amazing smoked eel and Westcombe Dairy for local cheeses. And as for good country pubs with a quieter atmosphere, there are plenty to be found in the villages around Glastonbury, including the Queen’s Arms in sleepy Corton Denham and the Talbot Inn in Mells.

Or for kitsch value, book a table at Who’d a Thought It, a cosy pub with old bicycles and skis on the ceiling and a telephone box with a mannequin next to the bar. From there you can stroll right on to Glastonbury high street as the carnival action starts.

• For more information about the West Country carnivals, visit somersetcarnivals.co.uk and glastonburycarnival.com