Why are sunrises and sunsets so spectacular during autumn and winter?

May 29, 2020

Gold Coast Sunset from Burleigh Heads (Image: Amanda Goddard)

Written by Shelley Lloyd, originally published on ABC News.

Meteorologists say the secret is in the cloud formations.(ABC News: Shelley Lloyd)

Social media feeds across the country have been ablaze with the spectacular colours of sunrise and sunset in recent days. As the days get shorter and colder, the skies seem to be getting brighter and bolder. From pink to red, orange and even purple, the start and end of our days during these colder months are more vivid than at any other time of the year. But why is that?

Meteorologists say the answer is quite simple. It’s to do with the clouds, the cold and the tilt of the Earth.

Gold Coast residents were treated to this spectacular start of the day earlier this week.(Supplied: Dean Johnson)

Cloud cover is key

Kimba Wong, a meteorologist with the Queensland Bureau of Meteorology (BOM) said when the right ingredients lined up, the environment served up a spectacular result.

“There are a couple of factors that contribute to creating the perfect environment for a really good sunrise or sunset,” Ms Wong said.

“What we’re looking for to create a really good sunset or sunrise — where we get really beautiful reds and pinks coming through — is mid to high-level cloud.

“That’s cloud that is not too close to the Earth’s surface, so that when the Sun starts to set or starts to rise, the angle of the Sun can hit up into the base of that cloud layer and refract back and give us those really beautiful colours as the light comes back down to the surface.”

But why does this happen more often in the colder months?

“The reason we get those sorts of cloud patterns in autumn and winter is because the angle of the Earth tilts a little bit further away from the Sun,” she said.

“Cold fronts that cross the continent are able to penetrate a little bit further north than in the summer.

“Those cold fronts really help give us that mid to high-level cloud … so it’s the cloud, the cold and the tilt of the Earth … all of these things come into play.”

The type of cloud also plays a part too.

The dry air in western Queensland makes for stunning crimson skies.(ABC News: Tony Rees)

Skies more spectacular in the west

“The most spectacular sunsets and sunrises we get are from the altostratus clouds, so that’s that mid-level layered cloud,” Ms Wong said.

“It looks like a quite a thick layer of white cloud during the day, but it’s thick enough to give us that really rich red and pink once the sun starts setting.

“If you go a little higher in the atmosphere, you get those wispy cirrus clouds and they can give you quite stunning sunsets as well, but the colour is usually not quite as rich as you get from the lower-level cloud.”

Sunrise seen over mudflats in Sandgate on Brisbane’s bayside.(Supplied: Robin Spencer)

Ms Wong said while there had been some fantastic skies across South East Queensland in recent days, the sky got even more spectacular the further west you went.

“If you go inland, you get the dry air through the surface layers of the atmosphere and that tends to give a slightly better chance of seeing those beautiful sunsets,” Ms Wong said.

“[That’s] because there’s no low cloud to block the beautiful colour coming through in the mid-level cloud.

“But really, you can see these beautiful sunsets and sunrises anywhere if the right ingredients line up.”

And it is not just Instagrammers and photographers who get excited about the perfect start and end to the day.

“From the office in the Brisbane city, we have a really beautiful view out to the west and over Mt Coot-tha as well,” Ms Wong said.

“So when you see that beautiful sunset going down behind Mt Coot-tha, you can see half the office rushing to the window to take a photo.”