Significance of weather and climate for tourism
Weather, climate and tourism are in diverse ways interconnected. Tourists and tour organisers need to be reliably informed about the role of weather in connection with tourism. One usually feels bad having to cancel a weekend trip because of crazy weather! Or what experience could be worse than a vacation with continuous rainy days? Also travel organisers or tour operators know through bad experience the important role played by the weather: Rainy summers and less snowy winters affects adversely the influx of tourists and consequently have a grave effect on the location and cash-box of tourist organisations.

But what about the climate ? Climate is defined as the mean conditions of the atmosphere and their extremes and determines if specific kinds of tourism are generally feasible or not at specific locations. The opinion has long been held that climate is somewhat constant. This notion is somehow particularly rampant within the circles of tourism administrators and travel organisers and should be corrected. Climate is not static but varies in space and time !

Definitions
Tourism is influenced by many factors two of which are weather and climate:
Weather: is the effective combination of atmospheric elements (physical condition of the atmosphere) at a specific time at a location and the resulting processes in the atmosphere (time scale: days).

Climate: is the typical representation of atmospheric and weather processes closed to the surface and the surface over for a location or an area over a long period of time with a characteristic distribution of frequency, mean and extreme meteorological values (time scale: years).

Tourism: is the entirety of the relationships, phenomena and experiences that arise from the travel and the stay of people in foreign locations or areas which are not their permanent places of residence and work.

Weather and climate as limiting factors in Tourism
The characteristics of weather and climate could scarcely disrupt human activities absolutely but could constitute a very important financial factor.
When viewed in the light of tourism, this implies that practically some regions of the world have a minimum tourism potential since their climatic conditions do not allow opportunities for tourism. Tourism administrators do not patronise such kind of areas since this does not yield significant profit.
The traveller, who however tours these regions would have make do with high costs in financial form (e. g. transport costs) or physical inconvenience (e. g. body strain). Financial loses can also result from weather variations and changes. Rainy summer or less snowy winters can have grave consequences on tourism.

Weather and climate as dominating factors of touristic demand
Weather and climate does not only shape the touristic offers but also the demand. They influence among others the decision about the destination or the kind of activities to be carried out. The climatic factors play a significant role in the three phases of a tour: before, during and after. The meteorological conditions affect also the design/construction of the day’s program.

Weather, climate, health and tourism
Trips in climate stressed areas of the earth can result in health problems (e. g. heat stress, UV-radiation, air pollution and heat stroke). A purposeful climate advisory service can help to prepare and protect travellers and particularly risk groups (the retired, the sick people and children) against the above mentioned.

Atmospheric Environment and effects on Humans

Thermal factors comprises the meteorological elements of air temperature, air humidity, wind velocity and short and long wave radiation which have a thermo physiological effect on man outdoors and indoors; the significance to health is associated with the close linking of thermoregulation and circulatory regulation.

Air quality factors comprises the solid. liquid and gaseous, natural and anthropogenic air pollutants which have an effect on human health outdoors and indoors; the air pollution conditions relevant to health depend on the emission sources and the transmission conditions (dispersion, dilution, possible chemical conversion, washout, rainout) which are determined by atmospheric stratification (turbulence state), wind, precipitation and possibly air humidity and solar radiation.

Actinic factors comprises the visible and ultraviolet spectrum of the solar radiation which has at direct biological action going beyond a purely thermal effect.

Odor: Human well-being may be impaired by noxious odors. The dispersion of odors depends greatly on local meteorological conditions (primarily thermal stratification and wind conditions).

Noise: Noise constitutes physiological stress for human beings, the level of which rises with increasing intensity and duration of the noise. The dispersion of noise is likewise influenced by local meteorological conditions (primarily thermal stratification and wind conditions).

Physiological Equivalent Temperature (PET) derived from the MEMI (Munich Energy Balance for Individuals) is defined for any location outdoors as the air temperature at which, in a typical indoor room, the heat balance of a human body is balanced at the same values of the skin and core temperature as for outdoor conditions. For a person sitting still and wearing ordinary indoor clothing, experience has shown optimum comfort at a Physiologically Equivalent Temperature PET of about 20 °C. At higher PET values, heat stress would be anticipated and at lower values cold stress. For other activities of different clothing conditions, the PET values required for comfort shift to higher values (less activity or less thinner clothing) or lower valued (increased activity or thicker clothing).