Yölämpötiloilla

Yölämpötiloilla is a Finnish term used in meteorology and related fields to refer to nighttime temperature conditions observed within a region or dataset. The word combines yö (night), lämpötila (temperature) and the adessive suffix -illa, indicating that the data pertain to nighttime temperatures. In practice, yölämpötiloilla may describe the range, average, or distribution of temperatures during the night, typically defined as the period between sunset and sunrise or as the hours around midnight to early morning, depending on the study.

Data are collected by national meteorological services and weather stations, often using the minimum night temperature as a key metric. Yölämpötiloilla data are used in climate analysis, crop planning, frost risk assessment, and energy consumption modeling, where nighttime temperatures influence plant development, frost events, and heating needs.

Trends in nighttime temperatures are a component of climate change studies. In many regions, nighttime warming has been observed, which can reduce frost events but also increase heat stress during warm nights and affect growing seasons. The term thus helps separate nocturnal conditions from daytime climate and supports applications in agriculture, ecology, and urban planning.

See also: diurnal temperature range, frost, nocturnal climate, meteorology, climate change.