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 03 DECEMBER 2024
Week 1 (Monday 09 December to Sunday 15 December)
At this stage, the second week of December, will likely be drier than average but also cooler or colder than normal too, owing to a signal to high pressure dominance. Warnings cannot be ruled out at this stage for frost, ice and low temperatures with these being the main weather hazards. Mist and fog could also set in, with the likelihood light winds on many on the days/nights.
Week 2 (Monday 16 December to Sunday 22 December)
During mid-December and the lead up to Christmas, conditions are expected to become mixed and unsettled. While there is a signal for wetter than usual conditions, mean air temperatures should recover to around normal values too – so a little milder overall with fewer frosty/icy early day and nights. Warnings cannot be ruled out at this stage.
Week 3 (Monday 23 December to Sunday 29 December)
Confidence decreases in the forecast for Week 3. However, there is a weak signal for further mixed or unsettled weather with wetter than usual conditions and around normal mean air temperatures. Warnings cannot be ruled out at this stage. Currently there is no indication of a White Christmas but do stay up to speed with the forecast and twice weekly monthly updates, as things can change.
Week 4 (Monday 30 December to Sunday 05 January)
Current indications for the final days of ’24 and early ones of ’25 are for mixed conditions with slightly wetter than usual weather and slightly milder than normal conditions persisting.
SEASONAL OUTLOOK FOR DECEMBER 2024, JANUARY AND FEBRUARY 2025 (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 possibility of precipitation trending near average overall.
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, colder than average periods, where all winter hazards are possible, could still occur at times throughout DJF.
The rainfall forecast is less certain. There is a slight signal for average to above average rainfall for the north and northwest of Ireland. There is also a slight signal for the south and east to have average to below average rainfall overall through the DJF period. There is potential for wetter and drier spells within the three months for all parts of the country.
The sea surface temperatures (SSTs) around Irish coasts and over the Atlantic are expected to continue above average during DJF. 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.