Why is it that especially on very cold mornings the temperature again drops after the sun has risen.?

Question

Why is it that especially on very cold mornings the temperature again drops after the sun has risen.?

Answer 1

becaus ethe sun has been down all night so there wasnt much heat and it rises but still has to take a little while to warm upp.

Answer 2

There are two possible answers.

If it is cold and the air is dry, this is likely the reason...

A very cold morning usually indicates a clear and stable air mass over the area.  In a stable air mass, the coldest will sink into a dense layer that is rest nest to the ground surface.  A standard weather instrument shelter, which holds inside all the meteorological instruments to measure the current weather conditions, sits about 5 to 6 feet off the surface of the ground.  During a cold and stable early morning hours, the coldest air will rest below the intrument shelter.  When the sun rises and starts to heat the ground, the cold air starts to mixed upward.  When this air finally mixes to the height of the instrument shelter, you will see a brief drop in temperature.  This drop in temperature is usually the lowest temperature of the morning.

If it is a cold morning and the air temperature is close to the dew point temperature (Clues: Relative Humidity is close to 100 percent or you see condensation (dew) forming on the grass or on parked cars), then this is the likely reason...

When the air is close to saturation in a cold morning, you will sometimes get condensation on the instument shelter and sometimes on the instrument itself.  This thin layer of liquid will act like a insolator during the cold morning.  Once the sun rises and starts to heat up the lower level, that thin layer of liquid will start to evaporate from the instrument shelter and from the instrument.  Evaporation is a cooling process.  That is why you feel cold when you get out of a pool or bath tub while you are still wet.  During the time the water is evaporating, the temperature will dip until all the water is evaporated.  Then the warming trend will restart again.  This dip is also likely the coolest reading of the morning since it uaually aout 15 to 45inutes after runrise.

Answer 3

The sun provides a source of lift (it warms the ground up a little, but colder air will take its place.) That's why it is colder on cold mornings though the sun has risen.