‘Lì qiū’ (立秋) is the 13th of the traditional Chinese 24 solar terms, marking the astronomical beginning of autumn—typically around August 7–9 each year. Literally, ‘lì’ means ‘to establish’ or ‘to begin’, and ‘qiū’ means ‘autumn’; together, they signify the official start of the autumn season in the lunisolar calendar. Though temperatures often remain warm in many regions, Lì qiū reflects a subtle shift: days gradually shorten, mornings cool, and agricultural activity turns toward harvest preparation.

This term appears frequently in traditional almanacs, weather forecasts, and cultural discussions about seasonal rhythms. It’s not just a meteorological marker but also carries cultural weight—people may eat specific foods (like peaches or watermelon) or follow customs to ‘ward off summer heat’ on this day. Unlike Western calendar-based seasons, Lì qiū is calculated precisely by the sun’s celestial longitude (135°), making it an integral part of China’s agrarian heritage and timekeeping system.