If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
People who live in the midlatitudes enjoy maximum daylight on the summer solstice and put up with maximum darkness on the winter solstice. Between the two extremes, sunlight increases or decreases each day, but the rate of change is not steady. It is least in midsummer and midwinter and greatest around the spring and fall equinoxes. The biggest shifts occur at very high latitude: Just before the period of total darkness (or just after total darkness), the sun is barely above the horizon around solar noon, when the solar elevation changes very slowly, resulting in a large daily difference in daylight minutes lost (or gained). People who live along the equator see no change; they experience a steady 12 hours of day and night throughout the year.
Credit: Jen Christiansen (graphic), Mapping Specialists (globes); Source: NOAA Solar Calculator
It’s Time to Stand Up for Science
If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.
I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.
If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.