When Summer Season Starts -

While the astronomical definition is precise in its calculation of celestial mechanics, it presents a meteorological paradox. On the summer solstice, the Earth receives the maximum influx of solar radiation (insolation). However, due to the thermal inertia of the oceans and landmasses, the peak atmospheric temperatures usually lag behind this solar maximum by four to six weeks. Therefore, under the astronomical definition, "summer" often encompasses the hottest months of the year (July and August), even as daylight hours begin to shorten immediately following the solstice.