Maynooth University (MU) researchers from the WASITUS project at the ICARUS Climate Research Centre, supported by colleagues at Met Éireann and Teagasc, have completed a rapid climate attribution study examining how climate change influenced Ireland's summer weather in 2026 and how these conditions are expected to evolve as global temperatures continue to rise.
The study comes at the end of a summer that brought exceptional warmth and prolonged dry conditions across parts of Ireland. It also follows the publication of the United Nations Environment Programme's Limiting Overshoot report, which warns that the world is on course to exceed 1.5°C of global warming and highlights the urgent need for both emissions reductions and climate adaptation measures.
In Ireland, climate change is already affecting key sectors such as agriculture. The Climate Change Advisory Council has warned that higher temperatures, shifting rainfall patterns and more frequent extremes could impact crop yields, fodder supplies, animal welfare and farm productivity.
The new study investigates how climate change contributed to the weather conditions experienced during summer 2026, with a particular focus on July's dry conditions and the role of increasing atmospheric drying.
A key measure used in the study is Potential Evapotranspiration (PET), which represents the amount of water that could be evaporated and transpired into the atmosphere if sufficient water were available. PET is widely used as an indicator of the atmosphere's drying power and provides insight into how rising temperatures can increase moisture loss from soils and vegetation.
Key findings
- Human-caused climate change has increased the likelihood of extreme July PET events in Ireland by approximately eight times and increased their intensity by around 7%. At 3°C of global warming, July PET levels are projected to be almost 6% higher than today.
- While exceptionally dry Julys are becoming less common overall, those that do occur are expected to produce even lower rainfall totals.
- The study found that elevated PET intensified the impacts of the low rainfall experienced during July 2026, worsening drought conditions across Ireland. Rising temperatures are increasingly driving summer drying through greater evaporation demand rather than through changes in rainfall alone.
- Summer temperatures continue to rise in line with climate projections. Warm summers are becoming more likely, while both daytime and nighttime temperatures are expected to increase further in the decades ahead.
- Ireland's agriculture sector is particularly vulnerable to these changes. As temperatures rise, soils are expected to become drier during summer months, making historically unusual dry-soil conditions increasingly common. The findings suggest that farmers and land managers should prepare for these conditions as part of a long-term trend rather than viewing summer 2026 as an isolated event.