coolweather

Coolweather is a descriptive term used to indicate intervals of cooler-than-average atmospheric conditions. It is not a formal meteorological category, but appears in weather reporting and climate discussion to convey a transient cooling period that contrasts with surrounding warmth. The term is used more in lay media and everyday language than in technical forecasts, where specific temperatures and conditions are described rather than labeled.

Coolweather can arise from a variety of factors, including intrusion of polar or continental air masses, radiational cooling under clear skies, and seasonal shifts in jet stream position. It often follows warm spells or is associated with a gradual transition between seasons. Local geography, cloud cover, and humidity modulate the severity of the cooling in any given region.

Regional expression of coolweather varies widely. In temperate zones, it commonly produces daytime highs roughly between 10 and 20°C (50-68°F) and cooler nights, while in subtropical areas the same label might apply to temperatures only modestly below the seasonal norm. In high latitudes, coolweather can align with near-seasonal averages.

Impacts include effects on agriculture, energy demand, and public health, as people adjust clothing and activities. Forecasting uses standard meteorological models; the label coolweather does not replace numerical forecasts but provides a simple qualitative description for communications and summaries. Some forecasts warn of frost risk during extended cool periods.

See also: cool spell, cold front, air mass, weather forecasting.