This page shows two of the most interesting tables (Humidex Index and Thom's Index) useful to evaluate how current temperature and relative humidity can affect the sultriness or discomfort sensation and cause health danger in the population.

During summer season, or in very hot periods anyway, the human organism makes use of perspiration to maintain its temperature within proper physiological limits. The sweat, which is most made of water, evaporates (endothermal phenomenum) taking away heat so as to have a cooling effect on the skin. An high humidity level in the surrounding environment may obstruct this process limiting the evaporation. The human body so can't eliminate the excessive heat (compared to its own physiological limits) receiving a sensation of an higher temperature.

Obviously all the formulas used to calculate the discomfort indexes produce theoretic average data which may be highly influenced by a lot of human and environmental factors such as: height, weight and sex of the individual, clothes used, presence of shade or wind, carried out activity, etc.

For graphical reasons in the tables you can find combinations of temperature (degrees Celsius) and relative humidity which can't really occur as they exceed the ability of our atmosphere to hold water vapour (e.g. temperature 38 C° and 90% relative humidity)

WINDCHILL FACTOR

REPORT

METEOMAR

FORECASTS

CHARTS

CLIMATE

OBSERVATIONS

WEBCAM

HEAT AND DISCOMFORT INDEX

HUMIDEX INDEX OF APPARENT TEMPERATURE ( degree C )

THOM'S DISCOMFORT INDEX