<span>The average number of daylight hours each month in Springfield in 2015:
Jan 9.5 Feb 10.5 Mar 12 Apr 13.25 May 14.5 Jun 15 Jul 14.75 Aug 13.75 Sep 12.5 Oct 11.0 Nov 9.75 Dec 9.25
Now, we observe the trend of the monthly hours, it starts with a low value then increases and decreases back to the original value. This represents a parabola with the highest point of 15 hours. </span><span />
