Srimad Bhagavatam Canto 10, Chapter 21, Text 16

SB 10.21.16

drstvatape vraja-pasun saha rama-gopaih
 sañcarayantam anu venum udirayantam
prema-pravrddha uditah kusumavalibhih
 sakhyur vyadhat sva-vapusambuda atapatram
In the company of Balarama and the cowherd boys, Lord Krsna is continually vibrating His flute as He herds all the animals of Vraja, even under the full heat of the summer sun. Seeing this, the cloud in the sky has expanded himself out of love. He is rising high and constructing out of his own body, with its multitude of flower-like droplets of water, an umbrella for the sake of his friend.
Srila Prabhupada states in his Krsna, the Supreme Personality of Godhead: “The scorching heat of the autumn sunshine was sometimes intolerable, and therefore the clouds in the sky appeared in sympathy above Krsna and Balarama and Their boyfriends while They engaged in blowing Their flutes. The clouds served as a soothing umbrella over Their heads just to make friendship with Krsna.”
Srimad Bhagavatam Canto 10, Chapter 21, Text 15
Srimad Bhagavatam Canto 10, Chapter 21, Text 17