Abu Khaldah said: I heard Anas bin Malik (may Allah be pleased with him), while he was sitting on a couch with al-Hakam, the governor of Basrah, saying that the Messenger of Allah (peace and blessings be upon him) "would delay the prayer until it was cooler when it was hot, and would pray early in the cold."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5679