Red sky at night shepherds’ delight; red sky in the morning, shepherds’ warning.

A well known weather saying indicating that the next day’s weather can be predicted from the colour of the evening sky or the same day’s from the sunrise.

Anyone with their head in the clouds
is likely to be a dreamer.

Every cloud has a silver lining.
Another saying; this time about life.  Even when bad things happen, good may come.

The sun shines out of that child.
Does this need any explanation?

Make hay while the sun shines.
Take an opportunity when the circumstances are favourable.

Ne’er cast a clout till May be out.
A clout here is an old-fashioned word for an item of clothing.  People argue about whether May is the month or the hawthorn blossom (or may, named for its flowering season).  In either case, it is best to know that summer has really arrived and there won’t be a sudden cold spell.

Not a cloud in the sky.
This is usually about someone’s circumstances.  Everything looks good, with nothing to worry about.

Out of the blue.
When the sky is blue, rain and sudden change are not expected.  So, if something happens out of the blue it is a complete surprise.

Like a bolt from the blue.
This one is more of a shock.  The bolt referred to being a thunderbolt.  Of course, it is well-known that if you hear the thunder, you have survived the lightning.  The use of weather sayings is rarely logical.  We even talk about the sun going behind a cloud, when we know very well that it is the cloud which has moved.

On cloud nine
signifies being very happy.

If someone is in cloud cuckoo land
he/she is living in an unreal world.

There are many passages in the Bible about the weather and God’s power over it and his promises about it.

One example is Genesis Chapter 8 verse 32 (NIV)

“As long as the earth endures,
seedtime and harvest,
cold and heat,
summer and winter,
day and night will never cease.”

Another is Psalm 29.