dawn to sunrise and from sunset to astronomical dusk in the entire year is 48º33'43". The maximum latitude to view both astronomical dawn to sunrise and from sunset to astronomical dusk in the months that includes autumn and winter is 63º26'07".

The nighttime/twilight boundary solar midnight's latitude varies depending on the month:

* In January or July, astronomical dawn to sunrise or sunset to astronomical dusk occurs at latitudes less than 48°50' North or South, because then the Sun's declination is less than 23°10'

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