Hi Aleksandra,
It's great to hear that you will be travelling to Ireland soon. The
weather in October is mostly sunny with some clouds. The average temperature is 50 degrees F.
There are lots of things to see and do in Athlone and its surrounding area. I would encourage you to
check out this page for more information.
In terms of Halloween, I would recommend that you check out the
Puca Festival is only around an hour from Athlone and promises to be a lot of fun. You will also find details of Halloween events in Athlone itself on the athlone.ie page.
Regards,
Eoin