Changes in Latitude

While we were there, I knew it. The scorching sun must be directly above Belize. My online research, however, didn't yield any affirming results. Given the fact that the sun is direct at about 23 degrees north latitude on the Summer Solstice, I figured that it moves about 1 degree per week (52 weeks/yr, 46 degrees/yr). Therefore, it would take about 5 weeks (after the Summer Solstice) for the sun to reach 18 degrees north latitude. My rough calculations led me to believe that mid May and late July are the hottest dates at our house, which - according to our GPS - is located at almost exactly 18 degrees north latitude.

Maybe I learned this in school, but I coudn't rememeber the term for the latitude at which the sun is directly overhead. So today I researched it some more and found the vital term: The sun’s declination is the angle between the rays of the sun and the plane of the earth’s equator. In other words, it’s the latitude at which sunlight is most direct. You can find the equation for the sun’s declination at http://en.wikipedia.org/wiki/Declination. And for an quick reference, here’s a link for the sun’s declination throughout the year: http://www.wsanford.com/~wsanford/exo/sundials/DEC_Sun.html

As this chart shows, the sun is most direct at 18 degrees north latitude on May 12th and August 1st. Good thing I wore sunscreen, because for the first time in my life I experienced the sun's most direct rays!