Highest synop pressures I can find today are (mbar):

1040.7 Malin Head 03980 15z - also 1040.5 14z, 18z
1040.5 Belmullet 03976 13, 14, 15z
1040.4 Connaught 03973 11z, 12z, 18z
1040.3 Claremorris 03970 11z

September British Isles records still stands - just - 1041.2 mbar at
Shawbury, Shropshire, 00 and 01 GMT 19 Sept 1986.

I am prepared to be corrected, but I'm 99% sure it's the earliest
'1040' on record in the British Isles - the August record (the lowest
of any month) is 1036.7 mbar, and we're only 10 days into September of
course.

1040 mbar or above has been reached in every month in the British
Isles except July and August, but 1050 mbar has been exceeded only in
midwinter.

(Monthly extremes from my paper in Weather, Feb 2007.)

--
Stephen Burt
Stratfield Mortimer, Berkshire