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: Tuesday 21st April 2026
Week 1 – Monday 27th April to Sunday 03rd May
Confidence is high during week 1, for a continuation of largely settled conditions, with high pressure centred close to or over Ireland. It’ll be much drier than average, with very little if any rainfall expected and it’ll also be warmer than average by a few degrees. Winds will be mostly light, occasionally moderate, with some sea breezes locally.
Week 2 – Monday 04th May to Sunday 10th May
During week 2, there’s a strong signal that it will turn more unsettled with low pressure becoming dominant. There’ll be rain or showers at times, with rainfall amounts expected to come in a little above average. Temperatures will drop too from the previous week to more like average values for the time of year.
Week 3 – Monday 11th May to Sunday 17th May
Confidence in the forecast decreases for week 3. However, there’s a signal for mixed and changeable conditions, with some showers or rain at times. There’s a signal for slightly higher than average rainfall in the east and north, with around normal rainfall totals expected elsewhere. There’ll be some drier spells too and overall it looks like temperatures will be around average to a little higher than normal for the time of year.
Week 4 – Monday 18th May to Sunday 24th May
By week 4, confidence in the forecast decreases further. However, there’s a signal for low pressure to be centred to the north of Scotland and high pressure over Central Europe, placing Ireland into a predominantly westerly airflow. There’s a signal for higher than average rainfall amounts generally, with drier conditions in some southern areas. Temperatures are likely to be around average, though possibly a little higher than normal along the east coast.
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.