Extended Range Forecast

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 and Met Éireann HQ during Storm Emma 2018

Images: Shutterstock/gabriel12. Met Éireann HQ during Storm Emma 2018



Week 1 (Monday 15 July to Sunday 21 July)

 Week 1 will bring changeable and mixed conditions with rain or showers at times, some of it heavy with a chance of thunder, but there’ll be good spells of drier weather mixed in too with sunshine. Rainfall amounts will vary, but will generally come in a little below average, though will be around average in southern areas. Temperatures will in general come in around normal, though a little below in parts of the south and west.


Week 2 (Monday 22 July to Sunday 28 July)

 Week 2 has a signal for low pressure to be signalled close to the northwest of Ireland. The weather will remain mixed with some rain or showers, especially in the west and north, but some drier spells too, the best of these in the east and south. Rainfall amounts will be close to average in the west and north, but below average elsewhere. Temperatures are likely to be close to the seasonal normal.


Week 3 (Monday 29 July to Sunday 04 August)

 While there isn’t any signal for either low pressure or high pressure to dominate, there’s an indication for drier than normal conditions for most on week 3. While the signal is weak, there’s the likelihood of temperatures being close to the seasonal normal.


Week 4 (Monday 05 August to Sunday 11 August)

 Confidence is low in the forecast for week 4, with little signal for either low pressure or high pressure to dominate and with just a slight signal for drier than average conditions in parts.




The signal from the C3S seasonal models for Ireland during the ASO period is for slightly above average temperatures. Rainfall amounts are less certain with the possibility of precipitation trending near average overall.

As mean temperatures during ASO are signalled to be above average overall, all three months are forecast to be between 0.2 and 1.0°C above normal, trending highest towards the end of the period.

The rainfall forecast is less certain, though there is the potential for drier spells, especially later in the period.

The sea surface temperatures around Irish coasts are expected to be average to slightly above average during ASO, trending 0.2 to 0.5°C degrees higher than normal generally, with the highest anomalies expected in the south.