Dáil Éireann Debate, Thursday - 16 July 2026
561. Deputy Roderic O'Gorman asked the Minister for Health if her Department or the HSE has collected statistics on excess heat related deaths in Ireland due to the heat wave experienced at the end of May 2026; and if she will make a statement on the matter. [54654/26]
View answer562. Deputy Roderic O'Gorman asked the Minister for Health her Department’s policy with respect to the collection of data related to heatwave events, in particular, excess mortality due to heat; and if she will make a statement on the matter. [54655/26]
View answerI propose to take Questions Nos. 561 and 562 together.
The Department of Health does not produce estimates of excess mortality. However, the Department works closely with the HSE-Health Protection Surveillance Centre (HPSC) and other stakeholders to monitor estimates of excess mortality.
Excess mortality is a term used in epidemiology and public health that refers to the number of deaths from all causes during a period of time above and beyond what we would have normally expected to see. Excess deaths are typically defined as the difference between the observed number of deaths in a specific time-period and the expected number of deaths during the same time-period.
A number of different methodologies have been developed internationally to try to estimate levels of excess mortality. All of these methodologies are statistical techniques to estimate excess mortality based on all-cause mortality data.
In Ireland, the HSE-Health Protection Surveillance Centre (HPSC) receives daily registered deaths data from the General Register Office (GRO) on all deaths from all causes registered in Ireland. These data have been used since 2009 to monitor excess all-cause deaths in Ireland as part of a wider European Mortality Monitoring Project known as EuroMOMO www.euromomo.eu/[]
EuroMOMO is a European mortality monitoring activity, aiming to detect and measure excess deaths related to seasonal influenza, heatwaves and other public health threats. EuroMOMO publishes a weekly update of estimates of excess mortality, by age group, for all participating European countries see www.euromomo.eu/graphs-and-maps[] This is the main indicator of excess mortality used in Ireland and by the Department.
EuroMOMO publish estimates in the form of z-scores. A z-score is a statistical measure that describes how far away from the mean a given data point is. In this context, if the observed number of deaths is the same as the expected number of deaths, the z-score is 0. The greater distance the observed number of deaths is from the expected number, the higher the z-score will be.
Weeks where the z-score is less than or equal to 2 are considered to not have any excess mortality. Where the z-score is greater than 2 but less than or equal to 4 is considered to be low excess; greater than 4 but less than or equal to 7 is considered to be moderate excess; and a z-score of 7 or higher is considered high excess.
The latest data published by EuroMOMO relates to Week 27 2026. For Ireland, no excess mortality has been recorded since Week 8 2026 (see attached chart). It should be noted that for more recent periods, these data are provisional due to the time lag with death registration in Ireland. A country-specific adjustment function is applied to correct for the typical lag in registrations of deaths in Ireland (the legal period for death registration in Ireland is currently three months). Nonetheless, estimates of excess mortality for the most recent weeks are reported with some uncertainty and should be interpreted with caution. EuroMOMO estimates of excess mortality are revised each week as additional data becomes available.
More broadly, the latest EuroMOMO bulletin noted that ‘This week’s pooled EuroMOMO estimates of all-cause mortality for the participating European countries show increased mortality around week 26, 2026. The increase is mainly seen in age groups above 45 years, particularly affecting some countries.’ The map attached shows the z-scores for Week 26 2026 for participating European countries with France and Belgium showing very high excess mortality and a number of other countries showing moderate or low excess mortality.
The Department of Health, together with the HSE-Health Protection Surveillance Centre (HPSC), continues to monitor estimates of excess mortality produced by EuroMOMO weekly.PQ_EuroMOMO_charts-z-scores-ireland.png
