Temperatures could reach as low as minus ten degrees as the cold snap hits this week.
Forecasters are predicting well-below-freezing temperatures to contend with at night time.
Met Eireann has issued a Status Orange - Low Temperature/Ice warning for the entire country until midday.
Despite this, the National Emergency Coordination Group have decided that schools will open.
Chair of the group, Keith Leonard, says the decision around school closures mostly lies with principals.
"Obviously, we're keeping a close eye on this with the Department of Education and looking at the overall weather conditions."
"Anything that would suggest 'blizzard' type conditions would put us into a different space again - that would have to be looked at."
"With the current conditions that are forecast as we are, I think we're happy that this is an issue for principals to take."
