Answer: sunniest

AnswerCrossword Clue
SUNNIESTMost cheerful.
SUNNIESTLeast clouded over
SUNNIESTMost genial
sunniest(of a place) Receiving much sunlight
sunniestSuggestive of the warmth or brightness of the sun
sunniest(of a person or their temperament) Cheery and bright
sunniestSUNNY, filled with sunlight
sunniestBright with sunlight