chilly

Chilly is an adjective used to describe weather or conditions that feel uncomfortably cold, but not freezing. It conveys a sense of coolness that may warrant warmer clothing or precautions. The term is common in everyday speech and tends to reflect personal perception of temperature rather than a precise measurement.

In practical use the temperature range associated with “chilly” varies by person and context, but it generally refers to mild cold that can be dampened by wind or humidity. Many English speakers consider 50–60°F (10–15°C) to be in the chilly zone, though perceptions shift with acclimation and season. Wind chill can make a day feel noticeably colder than the thermometer suggests.

Chilly can also describe non-temperature conditions, such as a chilly room or a chilly reception, where the sense of coldness is environmental or relational rather than meteorological. In literature and media the word is often used to set mood or atmosphere.

Etymology: chilly is a derivative of chill, formed with the adjectival suffix -y. It is used in informal speech and common writing to indicate moderate cold; it is less intense than cold and not as strong as icy in some contexts. The term has been in use in English since at least the early modern period.