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 FRIDAY 02 JANUARY 2026
Week 1 (Monday 05 January to Sunday 11 January)
Week 1 indicates a decline in high pressure with low pressure dominating conditions. There is a signal for below average temperatures for this time of year with a cold northerly airflow, with frosty nights expected. There is a signal for a return of more unsettled conditions with higher than average rainfall signalled across parts of the north, west and south.
Week 2 (Monday 12 January to Sunday 18 January)
While confidence in week 2 is lower, low pressure is signalled to continue. Wetter than average conditions are forecast for the majority of the country with slightly drier conditions expected in the northwest. Temperatures are expected to return to normal across the country for this time of year.
Week 3 (Monday 19 January to Sunday 25 January)
There is increasing uncertainty in the forecast for week 3. There is a slight signal for low pressure to continue dominating again this week, with rainfall also continuing to be above average nationwide. Mean air temperatures look to remain average for this time of year.
Week 4 (Monday 26 January to Sunday 01 February)
In week 4, the forecast confidence is low. The signal for low pressure over Ireland remains for the last week of January with predominately unsettled conditions. There is no signal for anomalous temperatures. Rainfall amounts are likely to be average for this time of year, with slightly wetter conditions expected in the west, while there is a signal for conditions to be slightly drier further north.
Seasonal Outlook for January February March 2026 (JFM):
The signal from the C3S seasonal models for Ireland during the JFM period is for above average temperatures. Rainfall amounts are less certain with the potential for wetter than average conditions overall.
Mean temperatures during JFM are signalled to be above average overall. Temperatures during the period are likely to trend between 0.5 and 1.0°C above normal, with the signal increasing through the period. However, colder than average periods, where all winter hazards are possible, could still occur at times throughout JFM, especially early on in the period.
There is a signal for above average rainfall overall, especially in the north and west of Ireland. This signal increases through JFM with March indicating the highest likelihood of above average rainfall out of the three months. Generally, there is potential for wetter and drier spells within the three months of JFM.
The sea surface temperatures (SSTs) around Irish coasts and over the Atlantic are expected to continue slightly above average during JFM. SSTs are trending 0.2 to 0.5 degrees higher than normal off the west and north coasts, with a trend of 0.5 to 1.0 degrees higher than normal off the south and east coasts.