Hot answers tagged sunrise
Around sunrise and sunset, the sun is much less intense. You would get around 5 times less intensity in the first or last hour of sunlight than in the middle of the day. Here is a graph of this effect (It's from a paper, though the paper itself is behind a paywall), and another one which also shows the effect of latitude. Therefore, while you can’t say ...
This web page should do the job, and also has a draggable map and list of cities if you want to select one of those rather than entering in manual co-ordinates. http://www.esrl.noaa.gov/gmd/grad/solcalc/
If you're old-school, here is a device I just learned about today (and it should fit into your pack): The Sunsetwheel. It's a sliderule type device, and may take a few minutes to learn how to use it, but it can give you data without having a smart phone on you at all times.
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