How to Make a Rainbow With a Garden Hose or Sprinkler

You can make a real rainbow in your yard by standing with the Sun behind you and looking toward fine mist from a garden hose or sprinkler. The water droplets bend and reflect sunlight just as raindrops do after a storm. This simple outdoor activity lets children experiment with light, position and color without special equipment.

What you need

Choose a sunny day, a garden hose with an adjustable fine-spray nozzle or a sprinkler, and a safe spot on grass where you can avoid soaking walkways. An adult should handle the water and check for slippery surfaces. You do not need soap, food coloring, mirrors or a prism.

Step-by-step: find the best rainbow angle

1. Go outside when the Sun is reasonably low, such as morning or late afternoon. Do not stare into the Sun.
2. Stand with your back toward sunlight and face an area of mist in front of you.
3. Set the nozzle to a fine, broad spray. A dense patch of small suspended droplets is easier to see than a narrow solid jet.
4. Look at the spray from a few different positions. Move gently left or right, or shift your height, until a colored arc appears.
5. Keep the Sun behind you as you photograph the result. If the arc disappears when you walk, the viewing angle has changed—not the chemistry of the water.

What a sprinkler rainbow looks like

This outdoor photograph shows the faint bands of color that appear where sunlight meets a sprinkler’s fine spray. A small close-up rainbow can be subtler than a dramatic storm rainbow.

Why do the colors separate?

Sunlight contains different visible wavelengths. When it enters a tiny water droplet, it bends (refracts); a portion reflects inside the drop and bends again as it leaves. Different wavelengths bend by slightly different amounts. The strongest colors of a primary rainbow reach you at angles around 40–42 degrees from the direction opposite the Sun. Millions of droplets together produce the colorful arc. For the general science, read how rainbows form from sunlight and raindrops.

Why can one child see a rainbow while another cannot?

Each person’s eyes receive light from a different set of droplets at the correct angle. A rainbow is viewpoint-dependent; it is not a fixed painted object hanging in one location. Stand a little to one side and you may see a slightly different arc. That makes a useful family science question: if you move two steps, which droplets appear to make your rainbow?

Can you see the whole rainbow circle?

In principle a primary rainbow forms a complete circle around the point opposite the Sun. The ground and your viewing position usually hide part of it. A sprinkler spray close to the ground usually shows only a segment, depending on where the droplets happen to be. Explore why rainbows are actually circles.

Frequently asked questions

Why isn’t my hose making a rainbow?

Try a finer mist, sunnier conditions, a lower Sun and a view with the Sun behind your shoulders. A solid stream has fewer droplets suspended in the right place for your eyes.

Will a cloudy day work?

A strong direct light source is best. Thick cloud cover can make the colors faint or invisible.

Does the color order change?

In the primary rainbow, red is usually along the outer edge and violet nearer the inner edge. A secondary rainbow, when visible, reverses the order.

Further reading

USGS Water Science School: Rainbows and National Weather Service: How rainbows form.