👉 The autumn fluid, also known as autumn rain or seasonal precipitation, refers to the weather phenomenon characterized by a significant increase in rainfall and cooler temperatures that typically occurs in the late summer or early fall of many temperate regions. This period marks a transition from warmer, drier conditions to cooler, wetter ones, often bringing vibrant foliage colors and replenishing water supplies. The term "fluid" emphasizes the sudden and substantial nature of these changes, affecting ecosystems, agriculture, and daily life as temperatures drop and precipitation levels rise.