en_tn_condensed/mat/16/02.md

When it is evening

The situation can be stated more clearly. Alternate translation: "If the sky is red in the evening" or "If the sky is red when the sun is setting" (See: rc://en/ta/man/translate/figs-explicit)

When it is evening

"When the sun is setting"

fair weather

This means clear, calm, and pleasant weather.

for the sky is red

As the sun is setting, Jews knew that if the color of the sky changes to red, it is a sign the next day will be clear and calm.