CORPUS CHRISTI, Texas — The summer solstice marks when the sun's direct rays are over the Tropic of Cancer and we receive the most insolation, or direct sunlight from the sun. It is also the longest day of the year before daylight starts decreasing.
The hottest days of the year come much later than the solstice. The average high temperature on June 21st is 92 degrees in Corpus Christi then climbs to 96 degrees from August 5 to the 15th which is the hottest period on average.
The phenomenon of the hottest weather following the summer solstice by a month or two is called the lag of the seasons.
Water absorbs a large amount of energy before it actually gets warmer due to it having a higher specific heat than land does. It physically heats up slower than the land. Water has a major influence on regulating air temperatures around the globe, especially around coastal areas. As a result, the warmest temperatures of the year will lag.
Think of it as trying to boil a pot of water. You can turn on the flame under the water but it takes a good amount of time after you put the heat into the water for the water temperature to actually increase and then come to a boil.