To create my ranking of the sunniest cities, I focus on the number of clear days first. I start with data provided by meteoblue climate diagrams which are based on 30 years of hourly weather model simulations. These numbers are by no means 100% perfect, but they do provide a general idea of a local climate.
meteoblue provides sunshine data as the number of sunny, partly cloudy, and overcast days in a month defined as follows:
- clear days – days with cloud cover below 20%—this is your typical most enjoyable day with blue skies,
- partly cloudy days – days with cloud cover between 20-80%—there’s some sun, but at times it can be obscured by clouds,
- overcast days – days with cloud cover over 80%—there’s little to no sun.
I add the monthly numbers to calculate how many clear, partly cloudy, and overcast days a location gets each year. I then exclude any location that gets more than 90 overcast days a year.
Why 90 days specifically? Because if you want to move to a sunny destination, you want to be certain of reliable sunshine year round. Clear days are the best indicator of how sunny a given place is.
Some big cities in which people complain about the lack of sunlight get on average between 100-150 days of overcast weather a year. For example, it’s cloudy for 122 days in Toronto, 140 in Berlin and 150 in London (that’s five months of gray skies!).
If someone wants to move to a sunnier climate, they probably want a notable difference instead of just a small improvement. For this reason, to create a ranking of truly sunny locations, I decided to focus on destinations with fewer than 90 overcast days a year, which means that 75% of the year will feature sunny or partly sunny weather.
This requirement excludes many destinations in otherwise warm tropical countries that get a long rainy season like Ecuador, Malaysia or Costa Rica. While many of them are very sunny for up to half a year, during the rainy season there can be as many as 15 or more cloudy days each month. The surprising fact is that in some of them, the gray skies can be almost as prevalent as in a cold, cloudy country like the United Kingdom. If your priority is to embrace the sunny lifestyle, would you really want to live in a place that’s cloudy for several months?
For example, in Bangkok it’s cloudy for 14 days in May, 16 in June, 18 in July, 21 in August and 19 in September. This means five months dominated by cloudy weather. It doesn’t strike me as the perfect destination for someone who wants sunny weather, even if it’s warm. Now compare it to Brisbane which gets 44 overcast days a year. Even on the cloudiest month on average, February, it’s only cloudy for 5 days. In which place would you rather live if you’re seeking reliable all year round sunshine?
Why Sunshine Hours Aren’t That Useful
Often, in articles about the sunniest places in the world, the metric used to define how sunny a place is are sunshine hours. I decided against using the number of sunshine hours because they don’t paint the full picture.
If you want to move to a sunny destination, you want to know how often on average it will be sunny. What does “2700 yearly sunshine hours” tell you? It might be useful for a general comparison, but you won’t know any specifics. On average, how cloudy are the winters? How sunny are the summers? Is the great majority of those sunshine hours spread over just a few months? The number of sunshine hours won’t help you answer these questions.
For example, I could tell you that Alicante, Spain, gets 2,953 sunshine hours a year. Let’s say that you live in London, which gets 1,633 sunshine hours a year. According to these numbers, Alicante is approximately twice as sunny as London. And that’s all you’re going to learn from the number of yearly sunshine hours. It might be useful, but it’s hard to imagine what it means that a place is twice as sunny.
Want more specific information? You need to know how many clear, partly cloudy, and overcast days each location gets on average a year.
Using meteoblue climate diagrams, we know that Alicante gets 116 clear days, 195 partly cloudy days, and 54 overcast days annually. London gets 35 clear days, 180 partly cloudy days, and 150 overcast days annually. This means that in Alicante you’ll see thrice as many clear days as in London. You won’t be able to learn this information from the number of yearly sunshine hours because it doesn’t take into account the cloud cover of each location.
If you dig deeper and check information for each month, you’ll get an even more detailed picture. For example, London gets only 2 clear days in January, while Alicante gets six times more—12. If we add the number of partly cloudy days in Alicante in January (11), you get 23 days of sunny or partly sunny weather in the middle of winter. In London, there are 10 partly cloudy days in January, which means that in total, you’ll get 12 days of sunny or partly sunny weather. In other words, in Alicante in January there’s at least some sun for almost 75% of the month, while it’s less than 40% for London.
These numbers paint a much more detailed picture than annual sunshine hours, don’t they?