yet the warmest summer days do not occur until july or august. the shortest day of the year is around december 21. yet the oldest winter days do not occur unti january or february. how can you explain these delays in hottest and coolest weather?
The longest day in the Northern Hemisphere is June 21st and you are correct in saying that the hottest temps of the Summer occur much later. The reason for this is because up until we reach the max temps, the Sun’s radiation has been mostly warming up the Earth’s surface from when it was frozen in the Winter. The incoming Sun’s radiation is effectively concentrated in the ground, heating the ground up. This is also a daily event as well because although the Sun’s max height in the sky occurs at noon (1PM in daylight savings time) the Sun’s incoming shortwave radiation is heating up the ground and then this heat is reflected back into the atmosphere as long wave (heat radiation) and that is why during Summer the hottest past of the day is typically in late afternoon.
It is a little different during our Winter as the Coldet day usually occurs near the beginning of January just 10 days after the shortest day of the year.
1) The land stores heat.
For example, you put a pan on the stove (nothing in it) and turn on the heat. After 5 minutes you take the pan off the heat and put your hands on the bottom. !!OUCH!! There i STILL heat available, even though you do not have it setting on the stove. the pan stores heat.
The land stores heat in just the same way it doesn’t get cold exactly when the sun goes down, and the coldest part of the night is at about 3:00 in the morning.
A HUGE land mass like a continent holds heat for MONTHS. And it als take weeks for it to get all warmed up. So, while the longest day of the year is in JUNE, the heat doesn’t build up until July or August.
And while the shortest day is December 21, the COLDEST days are in january and February.
2) Oceans and lakes do the same thing, but for much longer. water take a LONG time to heat up and a LONG time to cool down. So cities next to large lakes (like the great lakes) and oceans sty warmer longer and stay colder longer, too.
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Basically it’s because of radiation balance. The warmer the ground is, the more radiation it gives off. As long as there is more energy coming in than going out, it will continue to get warmer. So even though the MOST sunlight comes in on June 21st, even by late July the amount of sunlight is STILL more than the Earth is giving off. Once it gets to be less than that, it’s starts to finally cool off. The opposite is true in the winter.
References :
The longest day in the Northern Hemisphere is June 21st and you are correct in saying that the hottest temps of the Summer occur much later. The reason for this is because up until we reach the max temps, the Sun’s radiation has been mostly warming up the Earth’s surface from when it was frozen in the Winter. The incoming Sun’s radiation is effectively concentrated in the ground, heating the ground up. This is also a daily event as well because although the Sun’s max height in the sky occurs at noon (1PM in daylight savings time) the Sun’s incoming shortwave radiation is heating up the ground and then this heat is reflected back into the atmosphere as long wave (heat radiation) and that is why during Summer the hottest past of the day is typically in late afternoon.
It is a little different during our Winter as the Coldet day usually occurs near the beginning of January just 10 days after the shortest day of the year.
References :
Weather Expert