I have an AR that I want to spray paint (rattle can) on Sunday. The high for my part of the world is 59 degrees and dry. Is that too cool for spray painting?

Not at all. I have rattled many an item in temps as low as 50 degrees. Takes longer to dry, but doesn't make any difference in how long it lasts. I now have a woodstove in the shop for curing. Last couple I did were camo using a drywall sponge and rustoleum. Sprayed clear coat on top and set them up hanging from the ceiling not far from the heat. Worked great.

Cool, that's what I was hoping to hear. Thank you.

Just off the top of my head I think air circulation is more important than temp. Within reason.

I'm going to hang it from a tree (leafless) on the east side of the house when I paint it. Hopefully with a breeze and some sun it will dry reasonably well.

Pretty sure all the rattle cans say they need 50°F to properly dry.

I've used the wife's hairdryer a time or two to safely speed drying between coats, in similar temps....

Not sure hanging it outside is a good idea, lots more dust and crap in the air than people think.

de-grease, clean in detail every part that you're painting. Prep is the key to a good coating job.

I would second this

You’re overthinking it. Its a rattle can job. If you mess it up, just rattle can it again.

This ^ ^ ^
Wipe it with acetone and paint the blankety blanker

It's not like it's a restoration job on a 67 vette

I would prep and paint inside (garage, shop, etc.) then hang outside in the sun once flashed.

I've done a few. Light coats, as in the first coat may only give you 50% coverage. Second coat may or not give 100% coverage but don't worry about it, the third light coat will. Paint it where ever you need to, but just grab it by the wire and let it hang in your closed garage to dry and cure. I actually let one set up in a spare bathroom inside for an hour or so between coats. Plan on it taking a weekend. Drying and curing properly will give you great results.

Thanks everyone for chiming in. I’ve painted multiple ARs but it has always been in warmer weather. OS&W, that is beautiful work sir.