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 07 OCTOBER 2025
Week 1 (Monday 13 October to Sunday 19 October)
There is a strong signal for high pressure to be centered to the northwest of Ireland during the period, suggesting more settled weather. Mean air temperatures are expected to be average for this time of year, and slightly higher in the north and west of the country. Precipitation amounts are also likely to be below average as a result of the high-pressure signal.
Week 2 (Monday 20 October to Sunday 26 October)
Uncertainty in the forecast increases for week 2 but current signals suggest a return to lower pressure. Mean air temperatures are expected to be average for this time of year, with precipitation amounts expected to be above average for most of the country, with more average amounts signalled over west and northwest fringes.
Week 3 (Monday 27 October to Sunday 02 November)
While confidence is lower for week 3, the signal for low pressure persists. Mean air temperatures are expected to remain average for this time of year. Precipitation amounts are expected to continue above average across the country.
Week 4 (Monday 03 November to Sunday 09 November)
Very low confidence in the forecast for week 4. A slight signal remains for low pressure with mean air temperatures expected to remain average for this time of year. Precipitation amounts are likely to continue higher than average.
Seasonal Outlook for October November December 2025 (OND)
The signal from the C3S seasonal models for Ireland during the OND period is for above average temperatures.Rainfall amounts are less certain with the possibility of precipitation trending near average overall.
Mean temperatures during OND 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 winter hazards are possible, could still occur at times towards the end of OND.
The rainfall forecast is less certain. There is a slight signal for above average rainfall during October and a trend towards below average rainfall for November.Meanwhile, the signal for December is more mixed with the potential for both wetter and drier spells.
The sea surface temperatures (SSTs) around Irish coasts are expected to continue slightly above average during OND.