The IBTS says hospitals only have three to four days supply
The Irish Blood Transfusion Service (IBTS) is appealing for blood donors to come forward.
It is calling on blood donors to make a special effort to give blood over the coming weeks, as the sustained bad weather has adversely impacted the blood supply.
It says donor attendance at clinics has been significantly affected in the three week period since December 21st last.
The IBTS says this is also due to the fact that, in flooded areas of the country, safety advice has been to make only journeys that are absolutely necessary.
Operations director Paddy Bowler says: "This has resulted in blood supply levels of the main blood groups at three days".
"This will only sustain hospitals for the next three to four days. Blood is in constant demand and the IBTS aims to hold seven days supply across the blood groups".
"In an effort to improve the supply levels and maintain services to patients the IBTS is asking donors to make a special effort to attend clinics in the next two weeks and if you can, bring a new donor with you" he added.
IBTS has also scheduled additional clinics next Sunday January 17th in:
The IBTS has also thanked donors who attended clinics in adverse circumstances in the last three weeks.