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
MONTHLY FORECAST, ISSUED TUESDAY 11 NOVEMBER 2025
Week 1 (Monday 17 November to Sunday 23 November)
There is a signal for a northerly air-flow to become established over Ireland during the week as a Blocking High Pressure develops in the mid-Atlantic. The weather is likely to turn somewhat more settled with rainfall totals during the week forecast to be near or below normal. Mean air temperatures are likely to trend around or slightly below the climatological average.
Week 2 (Monday 24 November to Sunday 30 November)
The final week of November is likely to turn more unsettled as Low Pressure systems dominate Ireland’s weather. Rainfall amounts are forecast to be above normal, especially across the western half of the country. It is likely to turn milder than the preceding week with mean air temperatures predicted to rise above the November norm.
Week 3 (Monday 01 December to Sunday 07 December)
There is a trend towards unsettled weather for the first week of December with Low Pressure being more prevalent than normal for the time of the year. Rainfall totals are currently forecast to be above normal during the week. It is likely that temperatures will be slightly above the climatological average.
Week 4 (Monday 08 December to Sunday 14 December)
By Forecast Week 4, there is limited signal in the forecast data indicating the equal likelihood of settled or unsettled weather. This means that temperature trends are uncertain, with similar chances of experiencing above or below average values. Likewise, rainfall projections show no clear pattern, suggesting that conditions could range from relatively dry to wetter than normal.
Seasonal Outlook for December January February 2025-26 (DJF):
The signal from the C3S seasonal models for Ireland during the DJF period is for above average temperatures. Rainfall amounts are less certain with the potential for slightly wetter than average conditions overall, with both wetter and drier periods possible within the three months.
Mean temperatures during DJF are signalled to be above average overall. Temperatures during the period are likely to trend between 0.5 and 1.0°C above normal. However, there is a higher likelihood of cold spells occurring compared to recent winters, with all winter hazards possible, throughout DJF, especially in December.
The rainfall forecast is less certain. There is a slight signal for above average rainfall overall, especially in the north and northwest of Ireland. Generally, there is potential for wetter and drier spells within the three months of DJF.
The sea surface temperatures (SSTs) around Irish coasts and over the Atlantic are expected to continue slightly above average during DJF. SSTs are trending 0.5 to 1.0 degrees higher than normal generally, with a trend of 0.2 to 0.5 degrees higher than normal off northern coasts.