Toronto was treated to a stunning display of colours after a brief but powerful rainstorm earlier today. Anyone lucky enough to look up might've caught a glimpse of not one, but two rainbows arched over the skyline.

double rainbow #cntower #rainbow #toronto #cntowerweather

A post shared by Sára Metzger (@saccka) on Sep 7, 2017 at 12:58pm PDT

The phenomenon is as rare as it is complex. Basically, rainbows are the result of light reflected through raindrops which act like a prism, allowing us to see a spectrum of colours spread across the sky.

After the storm comes the (double) rainbow.

A post shared by HollyO △⃒⃘ (@hodobbs) on Sep 7, 2017 at 1:19pm PDT

In the case of the double rainbow, the second, slightly fainter rainbow is actually inverted, reflecting twice off the back of raindrops.

Never seen a rainbow this clear ever in my life. And my new office clearly has the best seat. #toronto #rainbow #torontorainbow #cityscape #torontocity #workdaymadebetter

A post shared by Hiren, design | coffee | read (@hirencreate) on Sep 7, 2017 at 1:10pm PDT

The reflections can go on forever, and there have been (albeit dubious) reports of triple, even quadruple rainbows. But today's double rainbow seemed to be enough for everyone to enjoy.