SEPTEMBER
2016
Wet and mild generally; very dull in places
Temperature: mild everywhere
All monthly mean temperatures were above their Long-Term Average (LTA) with differences from LTA over
1°C in parts of the Midlands and East. Deviations from average were as much as 1.6°C above at Dublin
(Phoenix Park) with a monthly mean temperature of 14.7°C, reporting its mildest September since 2006.
Most places which reported differences of over 1°C above LTA reported their mildest September in nine or
10 years. The highest temperatures of the month were mainly reported between the 5th and 7th, with the
month’s highest maximum reported at Dublin (Phoenix Park) on the 5th with 26.0°C, its highest for
September since 1961. Dublin Airport’s highest maximum (also reported on the 5th) of 25.1°C was its
highest during September since the station opened in 1942. A few other stations in the East and Midlands
also reported their highest maxima in nine to 25 years. The lowest air and grass minima were mainly reported
on the 21st, 22nd and 30th. The month’s lowest air temperature of 1.3°C was at Markree, Co Sligo on the
2nd while the month’s lowest grass minimum was at Mount Dillon, Co Roscommon on the 21st with -1.5°C.
Ground frost was reported at a small proportion of stations on the 21st and 22nd.
Rainfall: wettest September in 10 years at Valentia and Cork Airport
Percentage of September rainfall values were above LTA with exception of a few isolated stations in Dublin,
Donegal, Sligo and Mayo where monthly percentage values were just below LTA. Percentage of average
values ranged from 93% at Knock Airport with a monthly total of 103.2 mm, its wettest September in five
years to 156% at Newport, Co Mayo with a monthly total of 205.2 mm, its wettest September in six years.
Nearly three-quarters of stations reported it was their wettest September in five/six years with both Valentia
Observatory, Co Kerry and Cork Airport both having their wettest September in 10 years with monthly totals
of 182.7 mm (146% of LTA) and 136.3 mm (144% of LTA), respectively. The highest 24-hour rainfall total
occurred at Johnstown Castle, Co Wexford on the 3rd with 30.9 mm, its wettest September day since 2010.
The number of wet days (days with 1 mm or more) ranged from 12 days at Dublin Airport to 26 days at
Newport.
Sunshine: dullest September in over 50 years at Cork Airport
Dublin Airport had the highest monthly sunshine total with 112.4 hours (87% of LTA), but still reported its
dullest September in 16 years. The lowest monthly sunshine total was at Cork Airport with 68.2 hours (52%
of LTA), its dullest September since the station opened in 1962. The most sunshine reported in a day was at
Malin Head, Co Donegal* on the 13th with 10.5 hours. The number of dull days (days with less than 0.5 hours of
sunshine) ranged from four at Dublin Airport to ten at Valentia Observatory, Co Kerry*.
Wind: six days report gale force winds
Monthly mean wind speeds ranged from 5.8 knots (10.7 km/h) at Fermoy (Moore Park), Co Cork to
16.1 knots (29.8 km/h) at Mace Head, Co Galway. Just over half of stations had their windiest September
conditions in five years. Six days (the 9th, 11th, 23rd, 24th, 28th and 29th) had gale force winds, all in Atlantic
coastal areas, with the month’s highest gust and 10-minute wind speed both reported on the 23rd at
Belmullet, Co Mayo. The highest gust was 57 knots (106 km/h), its highest for September in five years while
the highest 10-minute wind speed was 42 knots (78km/h), its highest for September in 17 years.
EXTREME VALUES AT SYNOPTIC STATIONS
Rainfall
Temperature
Highest total: 205.2 mm (156% of LTA) at Newport, Co Mayo (its wettest September since 2010)
Lowest total: 56.6 mm (95% of LTA) at Dublin Airport
Highest daily rainfall: 30.9 mm on 3rd at Johnstown Castle, Co Wexford (its highest for September since 2010)
Highest mean monthly temperature: 14.7°C (1.6°C from LTA) at Dublin (Phoenix Park) (its highest for September since
2006)
Lowest mean monthly temperature: 12.5°C (0.5°C from LTA) at Knock Airport, Co Mayo
Highest air temperature: 26.0°C at Dublin (Phoenix Park) on 5th (its highest for September since 1961)
Lowest air temperature: 1.3°C at Markree, Co Sligo on 22nd
Lowest grass minimum temperature: -1.5°C at Mount Dillon, Co Roscommon on 21st (its highest for September since 2011)
Sunshine
Highest monthly total: 112.4 hrs (daily mean 3.8 hrs/day, 87% of LTA) at Dublin Airport
Lowest monthly total: 68.2 hrs (daily mean 2.3 hrs/day, 52% of LTA) at Cork Airport
Highest daily sunshine: 10.5 hrs at Malin Head, Co Donegal* on 13th
SEPTEMBER 2016 DAILY VALUES AT SELECTED SYNOPTIC STATIONS
DAILY (midnight to midnight UTC) RAINFALL
DAILY (midnight to midnight UTC) SUNSHINE HOURS
DAILY (midnight to midnight UTC) MAXIMUM TEMPERATURES
DAILY (midnight to midnight UTC) MINIMUM TEMPERATURES
l
Valentia Observatory*
l
Dublin Airport
l
Belmullet*
SEPTEMBER 2016 PERCENTAGE/DIFFERENCE FROM MONTHLY AVERAGES
RAINFALL (% OF AVERAGE FOR PERIOD 1981-2010)
Athenry, Co Galway
Ballyhaise, Co Cavan
Belmullet, Co Mayo
Casement Aerodrome, Co Dublin
Claremorris, Co Mayo
Cork Airport
Dublin Airport
Dunsany, Co Meath
Finner, Co Donegal
Gurteen, Co Tipperary
Johnstown Castle, Co Wexford
Knock Airport, Co Mayo
Mace Head, Co Galway
Malin Head, Co Donegal
Markree, Co Sligo
Fermoy (Moore Park), Co Cork
Mount Dillon, Co Roscommon
Mullingar, Co Westmeath
Newport, Co Mayo
Oak Park, Co Carlow
Phoenix Park, Co Dublin
Roche’s Point, Co Cork
Shannon Airport, Co Clare
Sherkin Island, Co Cork
Valentia Observatory, Co Kerry
TEMPERATURE (°C) (DIFFERENCE FROM AVERAGE FOR PERIOD 1981-2010)
Athenry, Co Galway
Ballyhaise, Co Cavan
Belmullet, Co Mayo
Casement Aerodrome, Co. Dublin
Claremorris, Co Mayo
Cork Airport
Dublin Airport
Dunsany, Co Meath
Finner, Co Donegal
Gurteen, Co Tipperary
Johnstown Castle, Co Wexford
Knock Airport, Co Mayo
Mace Head, Co Galway
Malin Head, Co Donegal
Markree, Co Sligo
Fermoy (Moore Park), Co Cork
Mount Dillon, Co Roscommon
Mullingar, Co Westmeath
Newport, Co Mayo
Oak Park, Co Carlow
Phoenix Park, Co Dublin
Roche’s Point, Co Cork
Shannon Airport, Co Clare
Sherkin Island, Co Cork
Valentia Observatory, Co Kerry
SUNSHINE (TOTAL NUMBER OF MONTHLY SUNSHINE HOURS)
Belmullet, Co Mayo*
Casement Aerodrome, Co Dublin
Cork Airport
Dublin Airport
Knock Airport, Co Mayo
Malin Head, Co Donegal*
Shannon Airport, Co Clare
Valentia Observatory, Co Kerry*
Issued by the Climatology and Observations Division of Met Éireann on Tuesday, 4th October 2016.
This report is based on available preliminary data from 25 principal weather stations operated by Met Éireann.
Synoptic station data is midnight to midnight UTC. Long-Term Averages (LTAs) and “average” refer to the period 1981-2010.
*Sunshine data is from the Autosol Network. LTAs for these sites are currently not used for comparison purposes.
For more information, contact Met Éireann at 01-8064200 or e-mail: [email protected]