inclement
adj.adj. describing bad or unpleasant weather, especially when it is very cold or rainy. It is a more formal and slightly old-fashioned way to talk about a stormy day.
adj. unpleasant or severe in weather; specifically, characterized by rain, snow, or cold. Often carries a literary or formal tone; frequently used in the phrase 'inclement weather'.
The hikers decided to turn back because of the inclement weather.
The airline canceled several flights after the storm brought inclement weather to the region for three consecutive days.
Despite the inclement conditions that greeted the explorers at the mountain pass, they pressed on, determined to reach the summit before the sun set.
From Latin inclēmēns (“unmerciful, severe”), from in- (“not”) + clēmēns (“mild, placid”).