Springtime has been with us for 92 days and even though today is a season shift, we’ve been experiencing summer for about five weeks. Today is the longest day of the year, marking the summer solstice. The sun is positioned at its furthest northern point, directly overhead at noon. Elsewhere, the warmest part of the day is afternoon when the sun is highest in the sky. As noted in a previous column, the heat kicks in due to the lag-time required for the ground and water to heat up. North of the Arctic Circle, there’s continuous sunshine for 24 hours. Sunset in Barrow, Alaska, won’t occur until Aug. 2. The sun appears for 161/4 hours along the U.S.-Canadian border and for 133/4 hours in Baton Rouge. Fastcast: Summer begins.