Apia has the second clearest sky in the Pacific, a ranking of the "blueness" of global cities' skies conducted by an Australian company has found. 

Suva, Fiji claimed first place for the Pacific's bluest sky. 

The study, conducted by the S Money company in conjunction with a colour expert, used Google Street View to find photos of a blue sky in every capital city in the world as well as the 25 most populous cities in the United States.

San Francisco, California was ranked as the American city with the bluest sky. 

The world’s Top 10 bluest skies were: 1) Suva, Fiji; 2) Nassau, Bahamas; 3) Phnom Penh, Cambodia; 4) San Jose, Costa Rica; 5) Paris, France; 6) Helsinki, Finland; 7) Oslo, Norway; 8) Bishkek, Krygyzstan; 9) Kiev, Ukraine and 10) San Francisco, California, United States.

“When sunlight hits the Earth’s atmosphere, it scatters into all the colours of the rainbow. Bam! Blue scatters the most because it has the smallest electromagnetic waves, giving the atmosphere a blue glow," a statement accompanying the survey said. 

"And so, there it is: blue is the colour of our bare sky. The colour you hope to see every morning when you wake up.

“But all blues are not made equal. Every city has its own range of hues. 

"The level of ‘blueness’ depends on factors, including the angle of the sun, cloud cover, and air pollution – perhaps that’s why many of us head for holiday destinations with famously blue skies. But which are the bluest on Earth?”

S Money worked with a data scientist to analyse images of the sky from every nation’s capital and ranked them on a consistent scale.

“Ranking them according to the CIELAB colour scale, we discovered which cities around the world have the bluest sky. And then we figured out the hex colour code for each sky so we could show you the results online,” S Money's report stated.

“Because the images were taken at different times, the result is not rigorously scientific. However, by using only images from sunny days, each city was granted a sporting chance at the top spot."

After finding photos of a blue sky in each city the ranking was based using colour analysis software - "ColorPick Eyedropper" - to rank the shades of blue according to their hex code (a computer code that can be used to rank colours). 

Some capitals were omitted due to the absence of any Street View photo without cloud cover.

“In order to rank the colours by blueness, we converted [red, green and blue] codes to CIELAB (a more sophisticated measure of how humans perceive colour), the colour space designed by the International Commission on Illustration to approximate human vision, which allowed us to isolate the amount of blue in each image,” the S Money statement read.

The study ranked the top 12 bluest Pacific skies as: 1) Suva, Fiji; 2) Apia, Samoa; 3) Wellington, New Zealand; 4) Canberra, Australia; 5) Ngerulmud, Palau; 6) Port Moresby, Papua New Guinea; 7) Honiara, Solomon Islands; 8) Majuro, Marshall Islands; 9) Port Vila, Vanuatu; 10) Palikir, Micronesia; 11) Funafuti, Tuvalu and 12) Tarawa, Kiribati.