Serving the Flathead Valley & Montana since 2006. A reality based independent journal of observation & analysis. © James Conner.
At high noon in Kalispell today, which occurs at 1225 MST, the sun will be just 21 degrees above the horizon. A six-foot man standing on main street will cast a 15.6-foot shadow due north, and someone driving due south may find no baseball cap has a bill long enough to block the glare. After 8.8 hours of sunlight, the sun will set at 1649 MST at a bearing of 239 degrees, southwest by west. Because our horizon is mountainous, the actual length of sunlight will be a little less than 8.8 hours.
With each passing day, the sun will sink lower at meridian passage until it bottoms out at 18 degrees on 21 December, the winter solstice and the first day of winter (but not the first day of wintry weather). At high noon on the solstice, our six-foot man’s shadow is 18.5 feet long, three times his height. Six months later, at the summer solstice on 21 June 2014, with the sun 65 degrees above the horizon at transit, his shadow will be 2.8 feet, roughly half his height, and shorter than his winter’s shadow by a factor of six.
When I was a student, calculating these values was a chore, and the libraries available to me didn’t always have printed tables of sunrise-transit-sunset times. Now, thanks to computers and the internet, calculating positions of astronomical objects and times of twilights, rises, transits, and sets, is within everyone’s grasp.
I calculated the values above, and a table for the charts below, with the U.S. Naval Observatory’s Multi-Year Interactive Computer Almanac, available from Willmann-Bell as a stand alone application and as online calculators at the USNO. There are many websites that calculate solar noon and the twilights. One of the best is www.suncalc.net by Vladimir Agafonkin, a Kiev based Ukrainian. Many hand-held GPS units calculate sunrise-transit-sunset times, but few calculate the azimuths of rises and sets, and the altitude of high noon. The MICA computes those values and more, including second-by-second values for azimuth and altitude, information enabling the use of a solar compass (that’s how one finds north with a digital watch).
How the sun’s altitude at high noon, and hours of sunlight, vary as a function of the time of year are displayed in the graphs below. A table of those values, and associated values such as the beginning and end of civil twilights, is available as an Excel spreadsheet. All times are standard time, so remember to add an hour when daylight saving time begins.
And to start the morning on a solemn but joyous note, Sunrise Sunset in a different context:
High Noon. Also known as solar noon, local noon, culmination, transit, and meridian passage, high noon occurs when the sun is directly above the meridian, at its highest point (altitude) in the sky. The clock time varies according to the meridian’s location relative to the eastern boundary of the time zone, the equation of time, and whether daylight saving time is in effect. If you’ve ever constructed a sundial, you know.
