Normally the average weather in Sligo for the month of October is 9 with the high being 13 and typical average low being around 9 celsius. We have put some more information here:
Sligo, Ireland Weather in October FAQs
What is the weather like?
You should expect to see 9 degrees on average
What is the average weather like in winter?
Normally the average weather in winter is 8 celsius.
Whats the difference in temperature between summer and winter?
Summer to Winter has a varience of 6 degree difference
Useful Links: Sligo Weather: Average Weather & Yearly Climate