Days getting shorter now, so why do temps keep climbing?

CHARLOTTE, NC (WBTV) - The new season is officially underway, but the longest day of the year won't be the warmest.  Why?  

There are two reasons that the hottest times of year in the Northern Hemisphere occur months after the Summer Solstice.

First, the oceans hold a lot of heat.  Air heats and cools much more quickly than water, so  with water covering roughly 70% of Earth's surface, it's going to have an impact.  When the sun heats land, it's only warming the thin upper surface of the land, but it will penetrate many meters into the ocean.  Also, the specific heat of water is about four times higher than land.  That means four times more heat is required to heat water by one degree than it would take to heat land.  It also means water loses heat much more slowly than land.

Also, even though days are getting shorter, we're not making dramatic changes in the length of the day.  We're only shaving off a minute or so from day to day which allows for many more long days when lots of sun can keep very warm temperatures in the forecast.  It isn't until after the equinox in September when we see longer nights than days.

The hottest temperatures in Charlotte generally occur in late July or early August.