Weather Blog

What's with the rainbow clouds?

What's with the rainbow clouds?
Photo of fire rainbow clouds taken on June 25, 2008 from Camano Island. (Photo: Shannon Brooks)

We've been getting several reports Wednesday afternoon of "rainbows in the sky" or clouds that are brilliant colors.

They're givien the coloquial name of "fire rainbows" and they are due high, wispy clouds that are made of tiny ice crystals, and if the cloud is at the right angle to the sun, the crystals will refract the sunlight (much like a prism) into the colors of the rainbow.

So it's very similar to a regular rainbow-when-it's-raining, only a little more rare.

These fire rainbows are rare sights in the mid-latitudes, because they can only occur when the sun is 58 degrees or higher above the horizon. For the United States in general that pretty much relegates any sightings to roughly around 6 weeks either side of the summer solstice.

The photo above was taken Wednesday afternoon from Shannon Brooks on Camano Island. I've attached some other photos at the bottom. If you have a photo of today's clouds e-mail me at scotts@komotv.com and I'll add them here.

Local weather lore is that when you see these types of rainbow clouds or a rainbow halo around the sun, it's a signal that rain is coming within 24 hours as these cirrus clouds typically come ahead of an approaching cold front.

But just like Punxsutawney Phil isn't right every year, rain in the short term is not the case this time. These are just some high clouds drifting in from offshore. Still no rain in the forecast.

There's more information on these clouds here in our Weather FAQ

P.S. I've had a few e-mails from people pointing to a YouTube video that is making the rounds showing similar clouds allegedly taken 10 minutes before the big quake in China.  I don't think there's any way to prove that claim is true, but even if so, I'd have to think it would be purely coincidental.  There is other stuff on the Internet about "Earthquake lights" and reports through the ages of Northern Lights-type lights before or after a seismic event. 

I'm not completely up on this, but I have to say that in today's event over Western Washington, the only places "lit" in rainbow colors were the clouds themselves, and the physics behind it just simply being ice crystals refracting the light is very solid.  Note that in that link above from our Weather FAQ, we have a gallery of several photos of rainbow clouds taken around here over the past few years, with no dire consequences. (And no, none were taken on Feb. 28, 2001 before the 6.8 Nisqually Quake.)