What causes frost to form?

Frost forms when water vapour in the air condenses directly into ice on surfaces that are below freezing. This typically happens on clear, calm nights when the ground loses heat rapidly and the surrounding air cools to its dew point. Frost crystals form intricate patterns on surfaces like grass, windows, and car roofs. The presence of frost indicates that temperatures have fallen below 0°C, making it a common phenomenon during autumn and winter in temperate regions.