I’m writing a Facebook Messenger bot and needed to send the degrees character to the user. The multitude of different ways didn’t work for me (\u00b0 etc.), but here’s a way that did:
// The rest of the messenger code here
$strToSend = "It's 13" . utf8_encode("°") . "C outside";
// And your code to send that message on
A short post, but hopefully it helps someone.