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 18 JULY 2025
Week 1 (Monday 21 July to Sunday 27 July)
Week 1 is indicating high pressure centred to the southwest of Ireland with low pressure centred to the northeast. This will bring changeable conditions although drier than average conditions are signalled overall. Mean air temperatures in week 1 will be mild with temperatures above normal for the time of year.
Week 2 (Monday 28 July to Sunday 03 August)
While confidence in week 2 is lower, there is a slight signal for high pressure to continue to dominate our weather. Current indications suggest conditions will turn more settled this week with rainfall amounts signalling below average temperatures across the country. Mean air temperatures are expected to be about average.
Week 3 (Monday 04 August to Sunday 10 August)
There is increasing uncertainty in the forecast for week 3. There is little change indicated this week, with atmospheric pressure continuing to signal slightly above average. Mean air temperatures are continuing to signal above average. The precipitation anomaly is also continuing to signal average rainfall amounts for most areas in week 3 with warmer conditions possible along southern coasts.
Week 4 (Monday 11 August to Sunday 17 August)
In week 4 the forecast confidence is low. There is no signal for either high or low pressure to dominate this week. While mean air temperatures look to again signal close to average, rainfall amounts are signalling more mixed conditions with greater than average rainfall in the west and northwest.
Seasonal Outlook for August September October (ASO)
The signal from the C3S seasonal models for Ireland during the ASO period is for above average temperatures, with average rainfall overall.
Mean temperatures during ASO are signalled to be above average. Temperatures are likely to trend between 0.5 and 1.0°C above average over the three-month period, with higher anomalies over mainland Europe during August continuing to have an influence at times.
The rainfall forecast is less certain, with the potential for both wetter and drier periods through ASO.
The sea surface temperatures around Irish coasts are expected to continue above average during ASO, trending 0.5 to 2.0°C higher than normal.