The antonyms for the phrase "bitterly cold" include: pleasantly warm, mild, temperate, balmy, and comfortable. These words describe a temperature that is not harsh or unbearable, but rather soothing and easy to tolerate. Pleasantly warm is ideal for outdoor activities, while mild temperature is perfect for outdoor picnics or strolls. Temperate is a perfect compromise between hot and cold, making it a good choice for everyday use. Balmy suggests a warm tropical climate ideal for relaxation and leisure. Comfortable temperature provides a sense of well-being, ensuring a sense of comfort in one's surroundings. These antonyms for bitterly cold can help to describe the perfect temperature for any occasion.