[skysurfer]

I live in northern EU on latitude 52 North. This results in very short summer nights (even with slight astronomical twilight). People in Scandinavia (60 N or higher) even have no nights at all in summer.
In that sense I prefer latitudes around 30-40 degrees or less. with no such extreme differences in summer / winter day length.

And sky coverage descreases when further from the Equator. Therretically, the Poles have only 50%, on 60º N/S it is 75%, on 52 N/S it is 81%, 30 N/S it is 93% and on the equator it is 100%. Considering objects must be at least 15 degrees high, these values are 69% for my latitude and 85% for 30 degrees, 98% for the equator.

And some desert locations have lots of hazy skies, usually in the Middle East and India.

Antarctica would be a nice location, but it is mostly heavily light polluted. Yes you read this correctly. No big cities or other human activities other than small scale scientific stations, but Aurora, which has a detrimental effect on astronomical observations, like you are observing from downtown Los Angeles or Dubai.


For observatories, the equator should be the best place, but the climate in most of the tropics is far more cloudy than around the thirties. Hence, the 39m E-ELT (and other Chilean observatories with scopes ranging till 8m) are between 24 and 30 S, the Keck in Hawaii is on 19 N, and the 10m scope in La Palma is on 29 N and the 10m Salt in Sutherland on 32 S.
Australia has no big telescope (yet ?) despite the climate is favorable for this. Maybe the lack of mountains > 2500m which other contintents / islands do have.

What do you consider as 'the best latitude' apart from the climate or number of clear skies ?