And it's good news for those out trick-or-treating as the weather is set to be dry for most of the day with witches casting just a few sunny spells by the afternoon.
Crumlin Road Gaol in Belfast will feature a special edition one-hour tour taking those who brave it around the various hot spots where paranormal activity has been reported.
Since its closure in 1996 there have been sightings, noises and unexplained happenings within the walls that have seen 17 men executed over its 150-year history.
Belfast City Council is to host the city's annual Halloween Monster Mash on the slipways of Titanic Belfast.
Beginning at 4pm, the entertainment line-up will feature street theatre and walkabouts, breathtaking fire shows and jugglers, face-painting, wicked workshops, fairground rides, on stage live music and Halloween fancy goods available for purchase.
This year's theme is Carnival Rock and monsters and ghouls of all ages can go in their show-stopping scary rock outfits or traditional spooky Halloween ones.
A firework display set to a classic rock soundtrack will mark the end of the evening. Ghost shuttle buses will also take you there for free.
Dust the cobwebs off your favourite costume as children in fancy dress get free entry to Belfast Zoo as part of the Boo At The Zoo event today.
Derry's devilish activities have got bigger and busier following the addition of the rise of the ghostly River Gods from the Foyle and further afield.
The city and district will be full of tricks and treats galore - with the return of the gruesome Chateau le Fear; the incredible spectacle of Awakening Of The Walls, and the addition of the Rio Bravo Fiesta celebrating Dia de los Muertos (Day of the Dead) hosted by the Craft Village.
And there is plenty of family fun lined up with child friendly shows, crafts, ghost tours, storytelling and more at the Alley Theatre and Strabane Library, and the Guildhall and Tower Museum.
The world renowned street carnival parade will end with the explosive fireworks finale.
The Share Discovery Village in Co Fermanagh is to host a spookily spectacular Halloween with fear-filled activities including a forest walk full of gruesome surprises. Fireworks display at 8.30pm.
Those who are brave enough can step aboard their ghost ship and enjoy a trip around the bay with story telling, games and ghoulish snacks on board.
A Little Spooks event will be taking place at the Navan Centre, Armagh until tomorrow
Have spooktacular fun as you meet with Hansel and Gretal at the witches' house in the woods.
Hallowtides Festival at the seaside town of Newcastle, Co Down will host a jam-packed calendar of spooky events as part of its annual Halloween celebrations.
Attractions will include live music, a fancy dress competition, float parade and one of the region's largest fireworks displays.