The Vietnamese word "nồm" refers to a specific type of weather, particularly a warm and humid southeasterly wind. It's often used to describe the climate in certain regions of Vietnam, especially during specific seasons. When you hear someone say "hôm nay nồm," it means "it is humid today."
While "nồm" primarily refers to the humid wind, it can sometimes be used in more poetic or descriptive ways to evoke feelings related to warmth and moisture.