National Forecast
Issued at: 20 September 2026 20:30
TONIGHT
Tonight will be mild, humid and mostly cloudy with patchy light rain or drizzle moving eastwards and mainly affecting the northern half of the country. There will be mist and hill fog too. Lowest temperatures of 10 to 15 degrees with light to moderate southerly or variable breezes.
TOMORROW - Monday 21st September
Monday will be mostly cloudy. There'll be some patchy light rain or drizzle and some mist or fog through the morning. Some sunny spells will break through during the afternoon and evening, the best of these, further south. Warm and humid, with highs of 17 to 22 or 23 degrees, coolest in the west and warmest in the east with light to moderate southwesterly breezes.
National Outlook
Overview: Turning rather mild and humid for early next week but still some rain and drizzle at times. Plenty of dry weather interludes also.
Monday Night: A very mild and humid night with a lot of dry weather and some clear spells, but still some mist and drizzle patches in the west and northwest. Fog patches possible in the south overnight too with lowest temperatures of 13 to 16 degrees in light to moderate southerly winds.
Tuesday: Becoming overcast during the morning with outbreaks of rain but more persistent rain will push in across Connacht and Ulster. Staying cloudy throughout the day with light southerly winds and highs of 17 to 20 degrees.
Tuesday Night: Cloudy with rain mainly across the west and northwest. Drier weather elsewhere but there will be some patchy outbreaks of light rain at times. Mist patches forming overnight too with light winds and lows of 11 to 14 degrees.
Wednesday: Cloudy, wet and unsettled to start but the rain will gradually move off the country in the morning leaving behind cloud for the afternoon and some dry weather and plenty of clear spells developing. Highs of 14 to 17 degrees with light northwesterly winds.
Further outlook: Current indications suggest that the unsettled weather will return for Thursday with some wet and possibly very windy conditions in store.
Temperature circle (°C): maximum and minimum temperature forecast for each day. Wind symbol (km/h): arrow points in the direction the wind is blowing. The weather and wind icons: for the time of maximum temperature and minimum temperature.