Fine rain or in Welsh "glaw man" on a rowan.
This is the type of drizzle that when I was a kid and wanting to go out and play you thought that you wouldn't get wet. But ended up soaked.
Apparently Ireland has "60 types of rain"
A gentle mist all heaven kissed
Like teardrops off an angel's wing
Don't you know you'll cleanse your soul
With a walk in the Irish rain.
Cho: Oh, Katherine, take my hand
I've got three pounds and change
And I'll sing you songs of love again
And when I get too drunk to sing
We'll walk in the Irish rain.