mostly likely something wrong with the sensor or gauge.
Defective temperature sensor or bad gauge
A temperature gauge, that always read the maximum temperature, is usually not connected to the temperature sensor. The wire between the gauge and the sensor must be broken.
If the temperature gauge needle doesn't go back to zero when the car is shut off, it is possible that the needle is sticking. A little WD-40 or electronic spray on the gauge might fix the problem. There could also be a problem with the MAP Sensor or a Radiator Pressure sensor in the engine.
In the middle (about 195 degrees).
the normally position of needle in temperature gage is a half of gage.
the gauge is the measurement of how big around the stud or needle is
The 21 gauge is a smaller needle.
Gauge is the term that indicates the diameter of the needle. Most commonly the needles that are used for medical purposed range from 7 Gauge to 33 Gauge, according to the Stubs scale. 7 Gauge needle will have the largest diameter while as the number increase, the diameter decreases. Therefore the 33 Gauge needle has the smallest diameter. So a 26 Gauge needle will have a smaller diameter than that of the 18 Gauge needle.
Yes, the larger the gauge the smaller the needle size.
normally the gauge should be in the middle.(between hot and cold) that is concider operating temp.
In any vehicle, when the radiator system is working correctly, the temperature gauge needle should be just below the half way mark when up to operating speed and temperature.