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relative_humidity

Functions:

  • calculate_relative_humidity –

    Function to calculate the relative humidity from dewpoint temperature and air temperature using the Sonntag formula.

calculate_relative_humidity 

calculate_relative_humidity(
    dewpoint_temperature, air_temperature
)

Function to calculate the relative humidity from dewpoint temperature and air temperature using the Sonntag formula.

Parameters:

  • dewpoint_temperature

    –

    dewpoint temperature in °C

  • air_temperature

    –

    air temperature in °C

References

[1] https://www.npl.co.uk/resources/q-a/dew-point-and-relative-humidity

Source code in reskit/util/relative_humidity.py 
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def calculate_relative_humidity(dewpoint_temperature, air_temperature):
    """
    Function to calculate the relative humidity from dewpoint temperature and air temperature using the Sonntag formula.

    Parameters
    ----------
    dewpoint_temperature: float | int
        dewpoint temperature in °C
    air_temperature: float | int
        air temperature in °C

    References
    ----------
    [1] https://www.npl.co.uk/resources/q-a/dew-point-and-relative-humidity
    """

    def calculate_vapor_pressure(temperature):
        """
        Function to calculate the vapor pressure from the temperature

        temperature: temperature in °C
        """
        temperature_Kelvin = temperature + 273.15
        vapor_pressure = np.exp(
            -6096.9385 / temperature_Kelvin
            + 21.2409642
            - 2.711193 * 10**-2 * temperature_Kelvin
            + 1.673952 * 10**-5 * temperature_Kelvin**2
            + 2.433502 * np.log(temperature_Kelvin)
        )  # vapor pressure [1]
        return vapor_pressure

    relative_humidity = (
        calculate_vapor_pressure(dewpoint_temperature) / calculate_vapor_pressure(air_temperature) * 100
    )  # [1]

    return relative_humidity