IPA: /ˈsʌn.wɜrdz/
KK: /sʌnˌwɜrdz/
In the direction of the sun.
The birds flew sunwards as the day began to warm up.
Sunwards → It is formed from "sun" (from Old English *sunne*, meaning the star that provides light and warmth) and "-wards" (meaning in the direction of). The word "sunwards" means in the direction of the sun.
Think of moving 'in the direction of' ('-wards') the 'star that provides light' ('sun') — that's why sunwards means towards the sun.