The Bible accurately reports how a red sky in the evening means fair weather, but in the morning it means rainy weather. Does this weather phenomenon also tell us something else? Could it perhaps even tell us something much more important than the weather forecast?

“The Pharisees and Sadducees came to Jesus and tested him by asking him to show them a sign from heaven. He replied, ‘When evening comes, you say, “It will be fair weather, for the sky is red,” and in the morning, “Today it will be stormy, for the sky is red and overcast.” You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times. A wicked and adulterous generation looks for a sign, but none will be given it except the sign of Jonah'”—Matthew 16:1-4 NIV

“The common phrase “red sky at morning” is a line from an ancient rhyme often repeated with variants by mariners and others:

Red sky at night, sailors’ delight.
Red sky at morning, sailors take warning.

The concept is over two thousand years old and is cited in the New Testament as established wisdom that prevailed among the Jews of the 1st century AD by Jesus in Matthew 16:2b–3" href="https://en.wikipedia.org/wiki/Matthew_16:2b%E2%80%933">Matthew 16:2-3.

If the morning skies are of an orange-red glow, it signifies a high-pressure air mass with stable air trapping particles, like dust, which scatters the sun’s blue light. This high pressure is moving towards the east, and a low-pressure system moves in from the west. Conversely, in order to see “red sky” in the evening, high-pressure air mass from the west scatters the blue light in the atmospheric particles, leaving the orange-red glow. High-pressure air mass signifies stable weather, while low pressure signifies unstable weather.

There are occasions where a storm system might rain itself out before reaching the observer (who had seen the morning red sky). For ships at sea, however, the wind and rough seas from an approaching storm system could still be a problem, even without rainfall.

Because of different prevailing wind patterns around the globe, the traditional rhyme is generally not correct at lower latitudes of both hemispheres, where prevailing winds are from east to west. The rhyme is generally correct at middle latitudes where, due to the rotation of the Earth, prevailing winds travel west to east.”—Wikipedia

The Bible accurately records how people from ancient times have been able to accurately forecast the weather based on the appearance of the sky.

“Jesus uses this familiar adage to illustrate the people’s ability to interpret earthly signs while remaining blind to spiritual truths. This also serves as a metaphor for spiritual discernment, urging the audience to recognize the signs of the times and the presence of the Messiah among them.

and in the morning, ‘Today it will be stormy, for the sky is red and overcast.’
This phrase reflects a common weather prediction method in the ancient Near East, where people observed the sky to forecast the weather. The red sky in the morning often indicated an incoming storm, a practice still recognized today. This reflects the practical wisdom and observational skills of the people during biblical times, who relied on natural signs for daily life decisions. The ability to interpret weather was crucial for agricultural societies dependent on favorable conditions for their crops.

You know how to interpret the appearance of the sky,
Here, Jesus acknowledges the people’s ability to discern natural phenomena. This skill is contrasted with their inability to discern spiritual truths. The emphasis is on the irony that while they can predict the weather, they fail to recognize the spiritual signs and the significance of Jesus’ ministry. This critique is directed at the religious leaders who were expected to guide the people spiritually but were blind to the fulfillment of prophecies concerning the Messiah.

but not the signs of the times.
The “signs of the times” refer to the prophetic indicators of the Messiah’s arrival and the unfolding of God’s redemptive plan. Jesus criticizes the religious leaders for their spiritual blindness and inability to recognize the fulfillment of Old Testament prophecies in His works and teachings. This phrase underscores the importance of spiritual discernment and awareness of God’s activity in the world. It also serves as a warning to be attentive to God’s revelation and not to miss His work due to preconceived notions or spiritual complacency.”—Bible Hub Study Bible

The account at Matthew 16:1-4 is instructive for us today. It’s useless in the long term to be wise in the ways of the world, and pay little attention to the far more important spiritual truths that God has set before us. As Jesus said in another setting, “What profit would there be be for one to gain the whole world and forfeit his life?” (Matthew 16:26 NAB). Indeed, spiritual discernment and awareness of God’s activity in the world are far more important than accurate weather forecasting.

People today, including Christians, often look for special signs of the end. Jesus indicated that there won’t be. “The sign of Jonah”, meaning Jesus’ death, burial, being in the tomb for three days, and being resurrected by God, is “the gospel” (1 Corinthians 15:1-4). “All scripture is inspired by God . . . so that the one who belongs to God may be competent, equipped for every good work” (2 Timothy 3:1,17 NAB).