The dew point occurs when the water vapor present in the atmosphere condenses.
The dew point is the moment at which the water vapor in the atmosphere condenses and generates, depending on the temperature, frost , fog or dew .
There is always water vapor in the air , the amount of which is linked to the level of humidity . When the relative humidity reaches 100%, air saturation occurs and the dew point is reached. It is important to note that relative humidity is the link between the amount of H2O vapor in the air and the maximum amount of H2O that could be present at the same temperature.
When the dew point is reached
When it is said that there is a relative humidity of 72% at 18ºC , for example, it is mentioned that the air houses 72% of the maximum amount of water vapor that it can have at 18ºC . If at this temperature , 100% relative humidity is reached, the dew point would be reached.
The dew point arrives, therefore, when the relative humidity increases and the temperature does not change or when the temperature decreases but the relative humidity is maintained.
If we return to previous values, we can say that, if the temperature remains constant at 18ºC and the relative humidity reaches 100% , the dew point will be reached and, therefore, the water in the air will condense. Thus there will be drops in the atmosphere ( fog ) and drops will also appear on the surface (dew). These drops in suspension or on the surface, of course, do not become wet as if they were precipitation (rain).
The dew point is linked to the humidity level.
Other information of interest
In addition to everything stated above, it is worth knowing other interesting data about the dew point, such as the following:
- The ideal dew point for humans is considered to be 10º.
- Experts in the meteorological field have stated that this element can be used to know the ease or even the difficulty with which the outer layer of the skin gives in to heat.
- In those places where it is considered that there is a high dew point, which exceeds, for example, 20º, it is established that the sensation of humidity and feeling hot flashes is very noticeable. This means, therefore, that it is difficult for the bodies of the people who are there to breathe and feel comfortable.
- For this well-being to occur, it is calculated that the dew point should be between 8º and 13º, while there should be no wind and that temperatures will reach a value between 20º and 26º.
Classification according to dew point
Specifically, the actual existing table on the dew point and its classification is as follows:
- Very dry air: dew point between -5º and -1º.
- Dry air: 0º to 4º.
- Dry well-being: 5º to 7º.
- Maximum well-being: 8º to 13º.
- Moist wellness. In this specific case, the dew point is between 14º and 16º.
- Humid heat: 17º to 19º.
- Sultry humid heat: 20º to 24º.
- Intolerable heat and very humid: 25º or more degrees dew point.