yölämpötilan

yölämpötila, Finnish for “night temperature”, refers to the temperature recorded at a location during the nighttime, typically between sunset and sunrise or at the lowest point of a daily temperature cycle. The term is commonly used in meteorology, climatology, and agriculture to assess nighttime cooling, soil and plant moisture conditions, and energy demand for heating and cooling. Nighttime temperatures are influenced by factors such as cloud cover, humidity, wind speed, topography, and surface characteristics. Clear skies and high wind speeds often lead to rapid cooling, while cloud cover can retain heat and keep nights warmer. Compared with daytime temperatures, night temperatures are usually lower but can sometimes exceed daytime values due to strong urban heat island effects. In many climate studies the difference between daytime and nighttime temperatures – the diurnal temperature range – is a key indicator of climate change impacts. In Finland the lowest night temperatures are often recorded in winter months, especially in inland and northern regions, while coastal areas maintain relatively milder night temperatures even in the coldest season. The measurement of yölämpötila is performed using standard meteorological stations, with data compiled by national weather services and used in climate monitoring, agricultural forecasting and energy planning.