Valmiki Ramayana Aranya Kanda Sarga 16 Shloka 19

पूर्वाह्णे in the forenoon, अग्राह्यवीर्यः when his(Sun's) heat cannot be felt, मध्याह्ने at midday, स्पर्शतः by touch, सुखः comfortable, संरक्तः red, किंचित् a little, आपाण्डुः whitish, आतपः heat, क्षितौ on earth, शोभते is delightful.

The heat of the Sun which we do not feel in the forenoon is comfortable during midday when the Sun shines slightly reddish white on earth.