"(if it is on it'll be tonight, Friday 9.30)"
It is usually cancelled for the Willie Clancy Summer School which is on now

THe Clé Club is on the 3rd Thursday in every month (except August) at Liberty Hall

The superb 'Larry' Night at th Cobblestone at Smithfield the firs Sunday of each month (don't know about the Summer Break

I've always found anything around Temple Bar as palatable as Doolin - not for me, I'm afraid

These are formal sessions - I'm told there are plenty of informal ones, but I've never visited them
A call to the Irish Traditional Music Arcice in Merrion Square might help
Good luck
Jim Carroll