Wrap up warm - cold and frosty conditions are set to dominate this week
Trick or treaters will have to wrap up warm for Halloween as cold, frosty conditions are set to dominate for the first half of the week.
Met Éireann is expecting temperatures to dip below freezing overnight tonight and tomorrow night, and could reach as low as -3C.
Forecasters warned that some roads may be affected by icy conditions, particularly this morning and tomorrow morning, with motorists urged to take care if using untreated roads.
Yesterday saw the first snow of the season with a dusting on some mountain tops.
Met Éireann said temperatures are lower than usual for this time of year and will remain so until it begins to warm up a little bit towards the second half of the week.
Temperatures are not expected to rise above 9C between today and Wednesday, and will range between -3C and 3C overnight.
Speaking on RTE Radio One's Morning Ireland, Met Éireann forecaster John Eagleton said the low temperatures are set to continue until Friday.
"Today will be another dry day for the bulk of Irelnd. It will be colder than yesterday and not as sunny," he said.
"Any sunshine today will be hazy due to the presence of a thin layer of cloud.
"It will be maybe a little sunnier tomorrow with the same temperatures.
"Wednesday and Thursday will be bright days with a few showers. These days will be dry, and it will be cold in the middle of the week.
"But there will be a big change on Friday," he continued, "it will be wet and windy with heavy rain.
"Back to today, there will be no rain but it will be dry and cold."
However, the cold temperatures didn't deter the more than 70,000 spectators who lined the streets of Galway last night as famed street theatre group Macnas provided a scare before bedtime for youngsters.
With the theme of 'Out of the Wild Sky', the Macnas Halloween Parade featured a flying Bird Man, a pack of fearsome wild wolves and eerie lumbering giants.
Organisers said it was a record-breaking turnout for the annual parade.
Tonight it will be the turn of Dubliners to enjoy the thrilling pyrotechnics, live music and more than 300 performers in fantastical costumes as the parade winds its way through the capital's streets as part of the Bram Stoker Festival.
The parade kicks off from Moore Street at 7pm and takes in Henry Street, Mary Street, Capel Street, Little Britain Street, Halston Street before finishing up on Mary's Lane.
Families are urged to take their spot on the route from 6.30pm and to wrap up against the cold.
Met Éireann said the cold conditions will continue up to Thursday.
Friday will be wet and very windy, with gales possible.