At what time of day would a rainbow be greatest?

Question

At what time of day would a rainbow be greatest?

Answer 1

The best view of a rainbow would be when the Sun is relatively low in the sky, such as a little after sunrise or a little before sunset.  That results in the rainbow being highest in the sky opposite the Sun.  The higher up the Sun, the lower the rainbow.

Answer 2

to make a rainbow spray water from a hose pipe in on a sunny day or use a prism and shine it in front of light bulb or shine the prism in the sunlight

Answer 3

As Cyswxman says, the lowest the sun, the greatest rainbow you will see. But a rainbow is always about 40 degrees in radius. The low sun will only show it higher in the sky but not wider.

As an airplane pilot I also get a chance to see a rainbow as a perfect circle under me. That happens when I fly e.g. right on the top of stratus clouds.