Saturday, August 18, 2012

Daylight and sun angles

On June 21st it was the longest day of the year and also when the sun is at its steepest angle above the horizon.  The angle of the sun was at 73 degrees at its highest point.  Currently the sun only gets to 62 degrees.  We have also lost 1.5 hours of daylight since June.  We are at 13.75 hours of daylight versus 15.25 hours on June 21.  This all translates into 1.5 hours less of intense heat stress on the turf.  Everyday we are losing a few minutes of the most intense part of the day.  From now until Mid October is when we have the best growing conditions for cool-season turf because of the lack of the intense mid-day sun we get in the peak summer months.