If you were on Facebook, Twitter or Instagram about 9 p.m. Sunday, you probably saw a few (or maybe a few hundred) sunset photos.

Or maybe you looked outside and saw the sun setting with your own eyes. That works, too.

We have the clouds to thank for the combination of soft pinks, yellows and reds that served as a background for all those Space Needle and Sounders photos, according to weather experts.

Sunday’s weather was the result of a low-pressure system from the south, National Weather Service meteorologist Jay Neher said. There were mid- to high-level clouds, with a few showers in the evening.

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Midlevel clouds provide gorgeous sunsets, according to Nick Bond, a state climatologist and University of Washington research scientist. Those clouds appear between 6,500 and 20,000 feet.

As the sun sets, the blue light, which is made up of short wavelengths, is scattered out by air molecules (that’s why the sky is blue) while the longer-wavelength red light shines from the side, rather than straight down. The midlevel clouds are in a good position to reflect that light, Bond said.

“While we got kind of ripped off in terms of rain, we did get the right kind of clouds to really give us a gorgeous sunset,” Bond said.

Good news: Though heavy pollution can be a factor in producing vibrant sunsets, air quality data suggest this wasn’t the case on Sunday, according to Bond.

“It was mostly just that we had the right kind of clouds,” he said.

There’s still hope for anyone who missed the sunset: We have a slideshow of sunset photos captured on Twitter. If that leaves you wanting more, a search for “Seattle sunset” on Instagram brings up 4,868 images.

And if you need some advice on the best techniques for shooting sunsets, here’s some help from the National Wildlife Federation.

Paige Cornwell: 206-464-2530 or pcornwell@seattletimes.com