Weather

Spring frost in cotton, orchards, vineyards and wheat

A spring frost is a short drop below zero when plants are already growing actively. Ice in the tissue ruptures cells and the tissue dies, but this shows only a few days later, as the plants warm up. Damage ranges from injured leaves to the loss of a whole orchard crop if frost hits during flowering.

Crops: Cotton, Orchards, Grapes, Wheat, Maize

When it is dangerous

Budding and flowering is the most dangerous stage: orchard flowers and fruitlets die after a brief frost of about −2 °C, and a similar frost at heading sharply cuts grain set in wheat. Seedlings are also at risk. Cotton is a warm-season crop with a base growth temperature of about 15 °C, and cold of 10–12 °C during seed swelling kills the young root.

Causes

Radiation cooling on a clear, calm night
An inflow of cold air with wind
Sowing warm-season crops too early
Cold air pooling in low spots

Signs on the field

Tissue loses turgor, darkens and turns brown
Blackened blossom in orchards
Bleached ears in wheat
The field loses green 4–10 days after the frost

How ClusterOS notices it

Frost is one of the few risks you can be warned about before it happens: ClusterOS follows the minimum temperature forecast and matches it to the crop's growth stage. The damage itself happens at night, and no satellite sees it at that moment. Sentinel-2 optical imagery shows the loss of green only 4–10 days later, because that is how long tissue death takes to develop, not a delay in imaging. A field check a few days after the frost confirms how severe the damage is.

What to do

If a clear, calm frosty night is forecast, prepare protection: sprinkler irrigation, smoke or wind machines
When cold air arrives with wind, protection does not work – inspect the field after the event
Do not rush sowing cotton and other warm-season crops in a cold spring
A few days after the frost, check darkened tissue and the condition of flowers

Questions

Can crops be protected from frost?

Yes, if it is a radiation frost on a clear, calm night. Sprinkler irrigation, smoke and wind machines help, and irrigated fields can use sprinklers. When cold air moves in with wind, protection is not possible.

Why does frost damage show up only after several days?

Tissue dies as it thaws, so the damage appears after 4–10 days. That is biology, not a satellite limitation. If those days are cloudy, the loss of green may show up in imagery even later.

Learn about this risk on your fields before it becomes a loss

We will show ClusterOS on your own fields: history since 2019, crop stage and all 24 risks.

Other risks in «Weather»

Scientific basis

Snyder R.L., de Melo-Abreu J.P. 2005, FAO Frost Protection
Frost Damage Index, PMC10550053
Spring cold stress, DOI: 10.3390/ijms232214099; Frontiers in Plant Science DOI: 10.3389/fpls.2019.00498
Physiological and Molecular Mechanisms of Freezing in Plants, 2025