When shall we three meet again?
In thunder, lightning, or in rain? (1.1.1–2)

The three witches speak these words at the opening of the play. Throughout the play, whenever the witches appear, there is thunder, rain, or some kind of bad weather that precedes them. The stormy weather associated with the witches symbolizes how their powers stir up trouble, incite chaos, and go against the natural order.

So foul and fair a day I have not seen. (1.3.38)

When the battle ends in Act I, a storm begins. Here, Macbeth notes how ironic this is, commenting on how odd it is to have such foul weather on such a fair and fortunate day. Even though Macbeth and his soldiers have won the battle, the weather turns violent, symbolizing that there is more danger and strife to come.

This castle hath a pleasant seat. The air
Nimbly and sweetly recommends itself
Unto our gentle senses. (1.6.1–3)

As King Duncan approaches Macbeth’s castle to celebrate their victory, he notes how nice the weather is. In this scene, the pleasant weather symbolizes the goodness and peace Duncan possesses and the natural order he represents. In contrast, whenever the witches appear, the weather turns chaotic and violent.

The night has been unruly. Where we lay,
Our chimneys were blown down . . .
Some say the Earth
Was feverous and did shake. (2.3.28–35)

The morning after Duncan’s murder, Lennox, a Scottish nobleman, remarks to Macbeth how bad the weather was the night before. Lennox says that the wind blew so hard that several chimneys were blown down, and it even seemed like there might have been an earthquake. These storms and natural catastrophes symbolize the disruption Duncan’s murder will cause to the natural order of human affairs.

By th’ clock ʼtis day,
And yet dark night strangles the travelling lamp. (2.4.6–7)

A Scottish nobleman, Ross, and an old man are speaking about Duncan’s recent murder. Ross notices that even though it is day, the sun is dark, an event possibly caused by a solar eclipse or a dark cloud blocking the sun. Whatever the cause, Ross comments that the skies appear to disagree with the natural order of things. The dark daytime skies are another symbol of disaster in human affairs and a violation of nature.