SOUTH BEND, Ind.-- Friday, March 20th, is the vernal equinox, the first day of Astronomical Spring. The vernal equinox doesn’t just mean the beginning of warmer days, but also longer days.
Equinox is derived from the Latin word “aequinoctium” which combines “aequus”, meaning “equal” and “nox”, meaning night. On the day of the equinox, the sun’s rays fall directly on the equator. When this happens, night and day are nearly equal, meaning about 12 hours of daylight. At the equator, the sun is directly overhead at noon. Since South Bend is about 40 degrees north of the equator, that’s not the case.
Friday, Michiana will have just over 12 hours of daylight. High latitudes enjoy slightly longer days. From here, daylight will continue to increase, until the first day of summer, when days will begin to shorten again.
Longer days also aid in boosting Vitamin D levels. Sun exposure is important, especially after the gloom of winter. However, it’s also imperative to know when vitamin D exposure comes impactful.
In the spring, the sun is higher in the sky compared to winter. At the beginning of January, the sun angle was 26 degrees. When the sun is higher, we receive more direct sunrays due to higher sun angles.
By the time March arrives, people’s vitamin D levels are typically at their lowest due to limited sunlight in winter. As spring continues, the sun angle continues to climb. April is the month where vitamin d exposure becomes significant, with a 56-degree sun angle at solar noon.
Experts say that the best time for natural Vitamin D intake is midday—between 10AM and 2PM, when the sun is highest in the sky. An afternoon walk during a lunch break would be a good opportunity to take advantage of sunlight. Always remember to wear sunscreen, even in the spring.