Warm spell to end with thunderstorms - 8th September 2021

The first half of this week brought warm and dry weather across Ireland, however the second half of the week will turn more unsettled and less warm along with the chance of thunderstorms.

Temperatures this week peaked at 28.3°C in Durrow, Co. Laois on Tuesday – this is provisionally the first time a temperature above 28°C has been recorded in Ireland on a September day in 30 years.  The last time temperatures reached 28°C was on 5th September 1991, with 28.4°C at Valentia, Co. Kerry.  Temperatures of 28°C or higher have only occurred three times in September since Met Éireann’s digital records began in the 1960’s.

The average maximum temperature for Ireland during September is around 17°C, while the average minimum temperature is 9°C. The highest September maximum temperature on record in Ireland is 29.1°C, recorded on 1st September in Kildare on Saturday 1 September 1906.

Around 10 weather stations across Ireland provisionally recorded new September maximum temperature records on Tuesday, including Sherkin Island, Claremorris and Shannon Airport.

Airmass Analysis chart from 00 UTC Sept 8th 2021

Airmass Analysis chart from 00 UTC Sept 8th 2021

However today (Wednesday 8th) brings a change in weather conditions as the warm airmass and high pressure is replaced by a less warm, more unstable airmass.  Met Éireann meteorologist Matthew Martin said: “We’ll still see temperatures reaching into the low 20’s Celsius in some areas over the next few days, but later this week and into the weekend temperatures will fall to around 16 to 19°C, which is more average for the time of year.”

“We also have a more unstable airmass moving in over the country and this will bring the chance of some heavy showers and thunderstorms through the rest of the week, though pinpointing when and where the thunderstorms will occur can be a challenge.

“Whilst many areas may avoid the heavy showers and thundery downpours, where they do occur it could lead to the risk of localised flooding and disruption to transport.  We’re therefore encouraging people to stay up to date with our forecasts and warnings, as well as our radar so they can keep an eye on thunderstorm development.”

Met Éireann has issued a nationwide Yellow thunderstorm warning valid from today until midday on Thursday 9th, where scattered heavy downpours and thunderstorms could lead to localised flooding in places.  The Met Office has a thunderstorm warning in place for Northern Ireland on Thursday.


Commenting on the forecast for the weekend, Matthew continued: “At the moment it looks like we’ll see a mix of sunny spells and scattered showers on Saturday and Sunday, although these showers aren’t expected to be as heavy as what we can expect over the next few days.

“There are signs of high pressure returning next week which could bring a more settled spell, however there’s still a good deal of uncertainty in the forecast at this early stage.”

Whatever the weather please follow the public health advice and help keep everybody safe from COVID-19.

For the most accurate and up to date 7-day, hourly forecast for your local area on the Island of Ireland go to met.ie. The latest weather advisories and warnings for Ireland are on the Met Éireann Warnings page. These services and more are available on our free app – available from the App store for iPhone, and Play store for Android. Follow us on Twitter and Facebook for extra weather and climate content.