Rainbow with a hose and the sun

Use a hose on a sunny day to split up the white light from the sun and make a rainbow.
Science content
Physics: Light and Sound (1)
Earth/Space: Weather, Seasons, Climate Change (K, 1, 4, 7)
Lessons activity is in
  • hose with a fine spray attachment
  • a sunny day

Face with your back to the sun while holding the hose, and ask the students to stand near you.
Set the hose on a fine spray (or depending on the attachment, the raindrop-like spray might work better), and spray the hose in a direction that produces a rainbow. Students may need to move around a little until they find it.
Ask them to tell you what colours they see in the rainbow. All those colours are in sunlight, and the drops of water separate those colours out so we can see them.
Compare to a picture of a real rainbow. The large rainbows are made in just the same way as the one with the hose - with raindrops and sunlight - you just need to be facing away from the sun to see the rainbow.

Older students can discuss how the rainbow is made in detail: the white light of the sun is reflected from the curved inside edge of the raindrop, but different colours bounce back at different angles (refraction), so the colours of white light are separated out. More detailed explanation on many websites including…

Grades taught
Gr K
Gr 1
Gr 2