why aren't the hottest days of the year the days with the longest daylight?

During the day the sun adds heat and it get warmer. At night heat radiates away into space and it cools down. As long as more heat is added during the day than radiates away at night it gets warmer over time. Even after the longest day of the year passes (about June 21, the first day of summer) there will be long enough days with direct enought sunlight to add more heat during the day than radiates away at night. So it will continue to get warmer for a good while longer. Certainly into July, and for many places, into August as well.

Well along with the tilt of the earth and the effect the suns rays have on the earth there are other factors that take place. For instance a cloud cover will often lower the amount of heat getting to the ground because a lot of it is radiated back into space. Proximaty to the ocean and wind direction also play a roll, the closer you are to the water generally the cooler the area because in the summer the water still has its winter chill and with that the wind will blow this cooler water on to the land. But if the wind changes in the other direction then you have the hot air blowing from and across the land bringing warmer days. The amount of airborne particles plays a roll as well, the more particles the more heat gets deflected. So although on June 21st the sun is directly of the Northern Hemsiphere and although it is the longest day, it may no nesessarily be the warmest. Think about this as well even though it is the longest day it has been rotating out of winter which is cold so much of the coldness of the winter is still around and as you progress into summer the winter coldness goes away and you get your summer heat. think of it as the earth is lagging behind the season.

Hope this helps,

Raven

How about a simple kitchen analogy? When I go to boil water on the stove I usually crank the burner all the way up to high to begin with, because I have to add a lot of heat to the water to get it to boiling. Even though I have maximum heat (like the days with longest daylight), the water is still relatively cool. Then once the water heats up, I can keep it boiling with the burner turned down a lot (like days later in the summer with less daylight).

Everything takes time to heat up and cool down, the Earth is no different.

The amount of solar radiation reaching a place on the surface depends upon many factors.The intensity of solar radiation diminishes due to the following reasons as it passes through the atmosphere.

Absorption and scattering by the molecule matter such as dust and smoke in the atmosphere reduces the intensity of the sunlight.Clouds are good reflectors of solar radiation and hence the presence of clouds will affect the amount of solar radiation reaching the earth's surface. ozone absorbs the ultra-violet part of the solar radiation.On reaching the earth's surface,part of the radiation is absorbed by the surface and part reflected into space ,the proportion depending upon the nature of the surface and inclination of the incident solar beam over that place.Solar radiation that is absorbed by the surface is transformed into heat.Part of this heat energy is radiated out to space as long-wave radiation,part carried upward as sensible heat by convection and turbulent eddies and part absorbed in evaporation processes from water surfaces if the place is nearer to large water surfaces.The remaining heat only penetrates downward to raise the temperature of the surface.

Even if the day time is longer over a place, some of the above mentioned factors may affect the incident solar radiation and make the day less warmer.

As the summer months progress so does the angle of the sunlight, that and every day the earth (as in ground, lakes, etc) absorb the heat and ground temperature rises, less escapes into space. So the air temperature rises Same thing in the winter (in reverse of course) the coldest days are rarely in December, but more likely late January and February.

BB

)O(

it all has to do with how directly the sun is shining that day.