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 27 JUNE 2025
Week 1 (Monday 30 June to Sunday 06 July)
Week 1 shows a signal for a continuation of mixed and changeable conditions with a westerly airflow likely to continue to dominate the weather. Temperatures are indicated to be average for this time of year, with a signal of above average in parts of the east and southeast. Rainfall amounts are expected to be below average for most of the country, with the exception of Northern Ireland which is signalling average or slightly above average precipitation amounts.
Week 2 (Monday 07 July to Sunday 13 July)
Confidence is lower for week 2, which signals a return of low pressure bringing unsettled weather conditions. Temperatures are expected to be average across the country for early July with rainfall amounts expected to be average or slightly above in northern regions and along Atlantic coasts.
Week 3 (Monday 14 July to Sunday 20 July)
There is increasing uncertainty in the forecast going into week 3 with no defining signal for low or high pressure over Ireland. Temperatures are expected to be above average in parts of the south and east with average temperatures elsewhere. Signals are also indicating that rainfall amounts will be average for mid- July with below average rainfall amounts expected in the northeast and far southeast.
Week 4 (Monday 21 July to Sunday 27 July)
Forecast confidence is low for week 4, though there is a slight signal for high pressure to build over most of the country which would bring more settled weather. Temperatures are indicated to be slightly warmer than average with below average rainfall amounts across the country.
Seasonal Outlook for July August September (JAS)
The signal from the C3S seasonal models for Ireland during the JAS period is for above average temperatures with average to below average rainfall overall.
Mean temperatures during JAS are very likely to be above average. Temperatures are likely to trend between 0.5 and 2.0°C above average generally with the highest mean temperatures, compared to average, signalled during July and August.
The rainfall forecast is less certain, with the potential for both wetter and drier periods through JAS, however, there is a signal for slightly drier than average conditions overall.
The sea surface temperatures around Irish coasts and over the Atlantic to the west and south of Ireland are expected to be above average during JAS, trending 0.5 to 2.0°C higher than normal generally. Sea surface temperatures are expected to be highest in comparison to normal off the south coast.