Hair growth is not directly affected by hot or cold weather, as it primarily depends on factors such as genetics, age, and overall health. However, certain environmental factors can indirectly influence hair growth by affecting the health of the scalp and hair follicles. For instance, dry and cold weather can cause dryness and flakiness of the scalp, which can clog the hair follicles and stunt hair growth. On the other hand, excessive humidity and heat can make the scalp oily and sweaty, leading to infections and hair fall. Therefore, it is advisable to maintain a healthy scalp and hair hygiene regardless of the weather conditions to ensure optimal hair growth.