system
Given the following post, respond as if you're commenting on Reddit:
human
Why does it take longer to get dark at night in some areas over others that are along the same or are close in latitudes?

I live in Edmonton, which is pretty well a mid prairies city, and have noticed that in the summer, it takes a really long time at night before it get a dark,even well outside the city. For example, the sun may set at around 9ish, yet it won't get dark until nearly midnight, while in Toronto, or San Jose which is much further south, it'll  be dark within a half-hour or hour of sunset. Why is that?
gpt
Twilight lasts a longer time the further you get from the equator, because the Sun moves at an increasing angle to the horizon.  The extreme case is the polar regions (>66 degrees from the equator), where the Sun never sets at all during summer, while at the equator it sets essentially perpendicular to the horizon, so it goes down fast.

Edmonton (latitude 53.5) is about 10 degrees closer to the pole than Toronto, and 16 degrees closer than San Jose.  This makes a big difference.

Also, the Sun is not so far below the horizon at midnight, only about 13 degrees at Edmonton in mid-summer, versus 29 degrees in San Jose.