Howya WWH

Them is the four seasons all right: samhradh, fomhar, geimhreadh agus (and) errach.

Regarding pronounciation people in different parts of the country pronounce Gaelic words differently, and as ya can imagine everyone thinks their version is the correct one (Connaught Irish, Ulster Irish, Munster Irish)

Here's Ted's effort and if I'm battered ta death by a band of vigilante Gaelgoirs (Gaelic pendantics), be it on your head.

Samradh - (very roughly) sow-rah
Fomhar - (ditto) four
Geimhreadh - (ditto) giv-ru
Errach - (ditto) ear-rah or ear-ock

The seasons themselves were not festivals, but each one was marked by the following feast day:
Bealtaine - May 1
Lughnasa - Aug 1
Samhain - Nov 1
Imbolc - Feb 1

GT