The extended range forecast, which includes the monthly and seasonal forecasts, can at times provide an insight into weather patterns in the months ahead. However, they should not be used for specific planning purposes as they have generally low skill compared with the 10-day forecast. This is because forecasts beyond one week become increasingly uncertain due to the chaotic nature of the atmosphere. Further information can be found here: Monthly and seasonal forecast explained.
Images: Shutterstock/gabriel12. Met Éireann HQ during Storm Emma 2018
Issued: 05/05/2026 13:00
Week 1 – Monday 11th May to Sunday 17th May
Low pressure is expected to dominate over this week, which will bring slightly wetter than normal conditions. Air
temperatures will be slightly cooler than normal in many midland, western and northwestern parts, but will be
around average for the time of year in eastern and southern coastal counties.
Week 2 – Monday 18th May to Sunday 24th May
While low pressure will still have an influence on our weather, there are signs of high pressure building closer to
the south-west of Ireland. As a result, it will be slightly wetter than average in most parts, but with near normal
amounts of rainfall close to the south coast.
Week 3 – Monday 25th May to Sunday 31st May
Confidence decreases into week 3, but current indications suggest that high pressure will continue to build from
the south-west pushing away the low pressure area towards Scandinavia. Rainfall amounts will be close to or
below normal, and temperatures will be close to the seasonal average in most places.
Week 4 – Monday 01st June to Sunday 07th June
Confidence is low but the current indications suggest that it will be generally a little drier than average with
temperatures around normal for early June.
Seasonal Outlook for May, June and July (MJJ)
The signal from the C3S seasonal models for Ireland during the MJJ period is for above average temperatures. Rainfall amounts are less certain with the possibility of precipitation trending near average overall.
Mean temperatures during MJJ are signalled to be above average overall. Temperatures are likely to trend between 0.2 and 1.0°C above average generally. The potential for warmer than average temperatures increases through June and July.
The rainfall forecast is less certain with no clear signal for above or below average rainfall overall. There is potential for both wetter and drier spells within the three months.
The sea surface temperatures around Irish coasts are expected to be above average during MJJ, trending 0.2 to 1.0°C degrees higher than normal generally. Sea surface temperatures are expected to be highest in comparison to average away from northwest coasts.