Wheat (Triticum aestivum L.) is one of the most crucial staple crops globally, providing essential calories and nutrients to a large portion of the world’s population. However, the production and quality of wheat are increasingly threatened by climate change, particularly by rising temperatures during the grain-filling period, commonly referred to as “terminal heat.” Terminal heat stress, occurring in the final stages of wheat development, can significantly impair grain yield and quality, posing a major challenge to global food security.The present research was conducted at the Student’s Instructional Farm (SIF) of Acharya N.D. University of Agriculture and Technology, Kumarganj, Ayodhya. Laboratory analysis was performed in the Crop Physiology Laboratory. The climate of Ayodhya falls under a semi-arid zone, with a mean annual rainfall of 1100 mm, about 80% of which occurs during the monsoon season (November to April), with occasional showers in winter.Three wheat varieties—PBW-343, HD-2967, and Kundan—were selected for the study, with three replications. PBW-343 and HD-2967 are high-yielding varieties commonly used in the North Eastern Plain Zone (NEPZ) for timely sown conditions, but they are susceptible to temperature stress. Kundan, a popular late-sown variety, is known for its tolerance to high-temperature stress. The treatments were based on three sowing dates: D1 (30th November), D2 (15th December), and D3 (30th December).