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 28th April 2026
Week 1 – Monday 04th May to Sunday 10th May
Week 1 is indicated to be mostly settled with high pressure dominating, generating a mostly slack airflow over the country. Drier than average conditions are expected countrywide but that does not preclude some rain and showers at times, particularly at the beginning and end of the week. Temperatures will likely be around normal. Given the slack airflow, fog is possible during the nights but will generally clear quickly in the mornings.
Week 2 – Monday 11th May to Sunday 17th May
Week 2 is indicated to be unsettled with low pressure systems tracking northeastwards over or near the country bringing wetter than average conditions though temperatures will likely continue around normal. Running rainfall accumulations could lead to some impacts.
Week 3 – Monday 18th May to Sunday 24th May
In Week 3, more mixed conditions are signalled with neither high pressure nor low pressure dominating, suggesting rain and showers at times but interspaced with drier conditions. However, rainfall accumulations will likely be above normal for all but some eastern and northeastern areas. Temperatures are indicated to be around normal.
Week 4 – Monday 25th May to Sunday 31st May
While there is a lot of uncertainty for Week 4, there is a signal for a slight improvement with normal amounts of precipitation likely away from northern and Atlantic areas. Temperatures are signalled to continue around normal.
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.