I bought a can of outside paint never opened it. Is it still good?

A sealed paint can still dry out... Only why to know is if you open it and stir it to see if it is hardened. Depending on the amount of time it sat... the color most likely separated... so you will need to re-mix it.

if it has never frozen, and when you shake it, it is still liquid, then yes, it is good

How old is it? If it has an "off" smell when you open it... trash it!

Depends on its age and how it was stored. Most paints state right o the label to not store at extreme temperatures. If really in doubt, call the manufacturer or look on their website for FAQs( Frequently asked questions).

If you bought it at Lowes or Home Depot, take it there and they can tell you. It will need to be shaken if it is still good and they will probably do it for free.

shoukd be good but will need to. S shaken