Helada vs. escarcha

The Spanish words 'helada' and 'escarcha' both describe conditions related to cold weather, specifically forms of frost. Although they may seem interchangeable, their use depends on the context and the specific type of frost being referred to.

Helada

'Helada' refers to a phenomenon in which the temperature drops below freezing, causing water vapor in the air to freeze and deposit on surfaces as a thin layer of ice. The term is often used in agriculture to describe conditions that can damage crops.
La helada de anoche dañó los cultivos de tomate.
(Last night's frost damaged the tomato crops.)
Nos despertamos con una helada que cubrió todo el jardín.
(We woke up to a frost that covered the whole garden.)
Es importante proteger las plantas antes de la primera helada del año.
(It's important to protect the plants before the year's first frost.)

Escarcha

'Escarcha' refers specifically to the deposit of small ice crystals that form on surfaces when water vapor in the air freezes. It often has a glistening appearance and is usually observed in the morning on grass, windows and cars. The term emphasizes the visual aspect of frost.
La escarcha sobre la hierba brilla con el sol de la mañana.
(The frost on the grass glistens with the morning sun.)
Tuvimos que raspar la escarcha del parabrisas para poder manejar.
(We had to scrape the frost off the windshield in order to drive.)
Las hojas estaban cubiertas de una fina capa de escarcha.
(The leaves were covered in a fine layer of frost.)

Summary

While both 'helada' and 'escarcha' refer to forms of frost, 'helada' is generally used to describe freezing conditions that can affect crops and other vegetation, emphasizing the effect of cold temperatures. 'Escarcha', on the other hand, emphasizes the presence of ice crystals formed from water vapor, often with a focus on their aesthetic appearance.