Solar Observation


Solar Observation


Observation Time

Shadow Length

Solar Angle

9/22 12:55 PM 57.0 0.81
9/23 12:55 PM 57.5 0.81
9/24 12:55 PM 58.0 0.80
10/3 12:55 PM 62.0 0.77
10/13 12:55 PM 72.0 0.69
10/18 12:55 PM 89.0 0.59
10/22 12:55 PM 104.0 0.52
10/30 12:55 PM 101.0 0.54
11/4*  12:55 PM* 127.0 0.44
11/23 11:55 AM 133.5 0.42

* Daylight Savings Time requires that measurements be taken one hour earlier, but I did not know to measure at 11:55 AM.  The 11/4 measurement was taken exactly one hour later than it should have been, which may skew the data slightly.

Date vs Solar Angle

The most difficult part about making precise measurements was measuring the shadow at exactly 12:55 PM once a week.  It was also difficult to measure the shadow when Daylight Savings Time started because I was in class every day at 11:55.  My data could have been improved if I measured the shadow with a tape-measure instead of a ruler, and also if I did not have class at the time we are supposed to measure the shadow.

The solar angle is the elevation angle of the Sun.  The solar angle of the Sun seems to decrease as time passes from September toward November.  The position of Earth in our orbit of the Sun causes the Sun to be lower in the sky.  The solar angle of the Sun will continue to decrease until the winter solstice around December 22.  Then, the solar angle will begin to increase again.

The greater the angle of the Sun at mid-day, the longer the day will be.  The winter solstice is the shortest day of the year, and the angle of the Sun is the lowest it will be in the sky.

The higher the Sun is at mid-day, the warmer the day will be.  As the Sun’s height decreases, the weather becomes colder (moving us toward the winter).  The length of the day relates to the weather because the shorter the day becomes, the colder the day will be.  The shortest day of the year occurs in the middle of the winter, around December 22nd, when it is very cold outside.