Thread: Differences in Sunset / Sunrise Times at Different Latitudes

Folks,

I am no scientist, so please humor and help answer this rather silly question.

I have a question about the average daylight hours experienced in some cities: Chennai, Mumbai (India), San Antonio, Texas, and Seattle, Washington

In summer:
In India, darkness falls around 6:30pm in Chennai (13 N). In Mumbai (19 N), darkness falls around 6:45pm, becoming complete by 7 pm. However, In San Antonio (29.5 N), darkness falls as late as 9pm, becoming complete by 9:30pm. In Seattle, by 8pm.

These Indian cities are much closer to the equator. Logic suggests that places near the equator should have the earliest sunrise and the latest sunset; as one travels northward, the amount of daylit hours should progressively reduce. But what I have seen is the opposite.

Can you explain this?

Near the equator, the days are nearly equal in length to the nights. At other latitudes, it varies with the season. In the summer, days are longer than nights, and in winter, the days will be shorter than the nights.

This is because in the summer, the earth's axis is tilted toward the sun. You can see the reason why by taking a world globe and tilting the north pole in your direction. If you imagine that you are the sun, you can see why you would "see" the north pole throughout the rotation of the globe. This means the sun would never set there at the summer solstice.

This is when it pays to have a globe with the 23 1/2 degree tilt mount. Once you see it in 3D, it becomes very clear.