how are max and min temperatures of a particular area calculated?

Answer 1

They are measured with special type of thermometers called 'maximum thermometer' and 'Minimum thermometer' .
The maximum thermometer has a constriction in the bore near the bulb.During expansion,mercury can pass through the constriction but not on subsequent contraction.Thus the end of the mercury column remains showing the maximium value.The maximum reading is taken and then the the re-setting is effected by shaking the thermometer at a particular time everyday.
The minimum thermometer caries a small index within the bore,below the surface the liquid(usally alcohol).Initial setting is effected by raising the bulb of the thermometer higher than the stem; the index then falls till its lower end meets the end of the spirit column,being prevented from further fall by surface tension.Contraction of the liquid on cooling causes the index to be dragged back closer to the bulb by the end of the spirit column,while expansin of the liquid by heating does not affect the position of the index.The position of that end of the index further from the bulb thus indicates the minimum temperature attained since the last setting of the thermometer.THe thermometer is supported so that the stem has slight slope downwards towards the bulb.With this arrangement, the movement of the index towards the bulb is slightly assisted by gravity.

Answer 2

You are probably talking about air parcels.

Air parcels are the main weather soundings forecasters use to find temperatures at a certain level in a certain layer of atmosphere.

Usually, the layers are calculated using "hectopascals" (acroynm--hPAs or HPAs) for the different atmospheric layers, such as the 500 HPA layer.

But there is more to this.....

They are looking for instability of the parcels, which are calculated in joules per kilogram as it pertains to Convective Available Potential Energy, which is used if any storm is forecasted in the soundings to approach the area where the sounding forecasts take place.

Convective means "pertaining to storm development" or "formation of clouds that eventually produce storms."

For instance.....

5,000 j/kg CAPE would mean a major tornado outbreak
(extreme instability) while 400 j/kg CAPE would mean only an isolated thunderstorm (marginal instability).

Getting back on how they calculate the parcels, they focus on the difference in temperature in the two air parcels. A warmer temperature above in one parcel and a lower temperature below in the other parcel means usually the atmosphere is stable. But if the reverse happens in the parcels, you set up things like lake-effect snow and all that because the reverse is usually a sign of
air parcel instability.

I hope all of this helps.

Answer 3

Good question and here is the scientific answer. There are thermometers which are designed specifically to measure the maximum and minimum daily temperatures. Each day at a specified time these instuments are read and recorded.

These are liquid in glass instruments. The maximum thermometer uses mercury while the minimum uses alcohol. There are many texts and web sites which explain the different mechanisms of the two instruments.

Answer 4

It's calculated between the specified sunrise and sunset timings as set by the Met Dept.

The Max is calculated on the degree where the mercury touches and Min is calculated where the mercury dips the lowest.

Answer 5

The temperatures are constantly monitored throughout day and night by the wea ther offices (known as Simla office at Pune.)and on that basis the max and min is worked out.