Does Dew Point Increase With Temperature: Detailed Facts

This article deals with the discussion and detailed facts on ‘does dew point increase with temperature?’

Dew point does not change with any temperature changes instead dew point is dependent on the relative humidity and pressure. Only under certain exceptional cases, dew point changes with respect to increasing or decreasing the system temperature. Changes in pressure or water vapor content leads to a change in dew point.

More detailed explanations on dew point will be discussed further.

Dew Point
Image Credits: Flickr

Dew point temperature chart

Dew point at different temperatures can be easily determined observing the dew point chart.

Also known as the dew point humidity chart, the dew point temperature chart helps us to estimate the dew point at a particular temperature and humidity value. The chart incorporates dew points at several temperatures and humidity levels.

does dew point increase with temperature
Dew Point Temperature Chart
Image Credits: Wikimedia Commons

From the above dew point temperature chart, one can easily determine the dew point at a specific temperature and humidity value. For example, when the temperature is 30 degree Celsius and the humidity is about 40 %, then the dew point will be 15 degree Celsius.

Frequently Asked Questions

Why does dew point increase with temperature?

It is a common notion that temperature and dew point are related and as temperature increases, dew point also increases.

There will be a change in dew point when the system temperature is at the saturation temperature or below the saturation temperature. The main reason why this happens is because water vapor is removed from the air.

In all other cases, the dew point is independent of the ambient temperature. Any change in pressure or relative humidity affects the dew point. Humidity, in turn, is dependent on temperature.

What is the relationship between dew point and temperature?

Dew point gives an indication of weather since it is related to humidity and temperature.

The dew point can be approximately determined from humidity and temperature by the following relation:

Where, Tdp is the dew point temperature in degree Celsius

T is air temperature in degree Celsius

RH is relative humidity in %

Relative Humidity, in turn, can be determined by the following formula:

Relative Humidity = {Mixing Ratio/Saturation Mixing Ratio} *100 %

Where mixing ratio is the value of actual amount of water vapor or moisture content in the air

Saturation mixing ratio is the value of amount of water vapor in the air when the air gets saturated.

Does dew point change throughout the day?

It is commonly observed that the dew point remains fairly constant all throughout the day. Even with changes in temperature, the value remains the same. However, this is true for closed systems, and hence there are occasions where wind movement affects the humidity and hence dew point.

For instance, consider a day when the air temperature is around 65 degrees Fahrenheit, the relative humidity is 100% and dew point is 65 degree Fahrenheit. Now if the air temperature rises to 80 or 90 degrees Fahrenheit, then the humidity changes to 60 % or 44% respectively, but there would be no change in the dew point.

What time of day is dew point highest?

Dew point is independent of the time of the day or air temperature. Its value becomes highest when the moisture content in air is highest. In other words, dew point will be highest when humidity is highest.

When the temperature is high and dew point is also high, we feel hot and humid as during summer days. When the temperature is low but the dew point is high, those are the times in cold winter days and nights where we feel bitter cold.

What is an uncomfortable dew point?

Some days in summer becomes oppressive due to heat, but it is actually due to humidity.

During summer, when the temperature rises and simultaneously humidity increases, the weather becomes intolerable. When value of the dew point is less than or equal to 55 degree then the weather will be dry and comfortable.

When its value is between 55 and 65 degrees, the weather becomes sticky and slightly uncomfortable. The value of dew point above 65 implies more humid climate which is oppressive.

Comfortable and Uncomfortable Dew Point
Image Credits: Flickr

As the dew point increases, the moisture content in the air also increases. This determines whether the climate is comfortable or not. This can be explained using an example. Consider a day with 30 degree Fahrenheit temperature and dew point 30. This implies humidity is 100%.

But the weather is uncomfortable when the temperature is 80 degrees and dew point rises to a value of 60 which, in turn produces a humidity of 50 %. The latter is more uncomfortable than the former even though humidity is less because dew point has increased in the latter.

Where are the highest dew points in the world?

Places with highest dew points would mean where humidity is very high.

World’s highest recorded dew point was at Dhahran, Saudi Arabia on the Persian Gulf. The recorded value was 95 degrees and was recorded on 8th of July in 2003. The next highest dew point was recorded by a weather historian at Moorhead, Minnesota on 19th July 2011 and the dew point value was 88.

Similarly dew point of 88 was recorded at Newton, Iowa on 14th of July 2010, a dew point of 90 was recorded at Appleton on 13th of July, 1995. Another high dew point was recorded on 12th July, 1987 at Melbourne and the value was about 91.

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