It wasn't when I was a kid - we held back until 5 November, when we celebrate being a tolerant and liberal country by burning effigies of Roman Catholics and setting off fireworks. Something which, understandably, only enhances the belief held by citizens of other countries who encounter this that Brits really are batshit crazy. You'd see kids pushing effigies around a few days before, asking for "a penny for the guy". Last time I saw anyone do that must have been in the 1980s, and I was mean enough then to look at the kid and say "a penny? OK" before giving him 1p. He didn't look very impressed, but hey - it's what he asked for.
However, these days it's Halloween, which is much more fun, though not on the same scale that you have it in the US. You'll probably find people on this forum who moan about it being an American thing, but actually Halloween has been appropriated for a very long time. It used to a pagan festival called Samhain (apparently, the Irish word for November is Samhain even today), the day of the dead, and the half way point between the autumn equinoxe and the winter solstice. Early Christians appropriated it and turned the following day into "All Saints Day", making 31 October the eve of the Saints day, or Halloween. The Catholic church also had All Souls Day on 2 November where you pray for the souls of those in purgatory.
In our area, the local kids come round in fancy dress - it's quite a family thing, as the very young ones come round in little groups with a couple of adults. They tend to knock on the doors of people who have pumpkins outside, as they know they'll get some sweets there. We usually have a couple of friends round and dress up and have sweets for the neighbourhood kids who call, but this year we're going to our friends' house instead.