Sunrise, Sunset, and Twilight! What are your city's times for today? (days, degree)
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
Daylength threshold is when the very top tip of the sun visible in the horizon. Which is 16 arc-minutes from the sun's centre, plus 34 arc-minutes from the athmosphere's refraction = 50 arcminutes sun elevation helow the horizon
The map Cambium posted is daylength on sea level, for elevation x metres, add approximately 1/29 of sqrt(x). degrees. For x feet (imperial) add around 1/52 sqrt(x) degrees to that 50 arcminutes
Last edited by divisionbyzero0; 03-17-2016 at 12:00 AM..
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
