Current meteorological data
Air temperature: 45.32 (°F)
7.4 (°C)
Wind speed:4 (km/h)
Wind direction: S-S-W, 191.3 °
Global radiation: 0.0 (W/m²)
Act. UV-Index: 0
Precipitation: 0.0 (ltr/m²)
(Updated: 03/19/2024, 04:30,
S-Mitte, Amt für Umweltschutz
More meteorological data
More about weather Stuttgart
Current sun location
Webcams in Stuttgart
Weather forecast Stuttgart 
Weather forecast Europe 
Weather radar Germany 
More links

News and current events
Meteorological Annual Report 2023, Stuttgart Hohenheim
Annual Report 2023
Particulate matter in Stuttgart on New Year's eve 2023 (German)
PM10 and PM2.5 (New Year's eve)
Climate Center Stuttgart
Climate Dashboard Stuttgart
Summer Days and Hot Days in Stuttgart (until 2023)
Air: Press releases (German)
UV-Index Prognosis (BfS)
Urban climate Viewer: Maps and plans with detailed thematic maps on climate, air and noise
Noise Maps Stuttgart 2022
Noise action plan Stuttgart
Clean air plan Stuttgart
NO2 and PM10 exceedances
Current measurements from the stations (LUBW)
Picture gallery      More news
Introduction

The urban climate is modified by the influence of built-up areas and their implications (including waste heat and pollutant emissions) (definition according to the World Meteorological Organization WMO, 1981).

The development of our weather follows physical laws, with rapid changes in the atmospheric conditions being a typical element.


Determining factors of the urban heat balance (according to ROBEL et al., 1978)
The climate, however, is defined as the average state of atmospheric conditions with their range of variations at a certain place. Determining factors are the geographical position and altitude of a place and its proximity to large water surfaces. The climate is defined by the climatic elements air temperature, humidity, precipitation, air pressure, wind, clouds and radiation.

This definition shows that "the climate" cannot be quantified through a measured variable. In consequence, what can only be measured, monitored and evaluated are single climatic elements. The Academy for Spatial Research and Planning (Akademie für Raumforschung und Landesplanung, ARL) has published meteorological definitions for regional planning as work sheets (SCHIRMER, 1988). Bioclimatology, a science which studies the effects of climate on living organisms, tries to link different climatic elements and give a mostly subjective evaluation. This is the case for thermal stress ("sultriness") as a combination of the elements air temperature, humidity and radiation.

One of the main tasks of climatologists is the synthesis of all climatic elements with simultaneous consideration of their interdependency and of extraneous influences (like type of surface, relief, development structure).

Besides mostly time-consuming and expensive measurements, everyone can watch nature and observe and evaluate climatic conditions. You can observe, for example, trails of smoke as an indicator for the direction of the wind and the thermal stratification of the atmosphere, vegetation and its growth as an indicator for temperature and precipitation as well as ground fog areas as an indicator for local pools of cold air. Another example is the observation of frost damages and local cloud formations.

While the climate in undeveloped areas largely depends on natural conditions and factors, the climate in towns and cities is influenced by buildings and is called the urban climate. The term "urban climate" nowadays also includes changes in the natural composition of the air as a consequence of man-made influences (like corrosive gases and aerosols).

Characteristics of the urban climate of a city in the temperate zone (KUTTLER, 2004)

Determining factors Difference compared to the undeveloped surrounding region
Global radiation (horizontal surface) up to -10 %
Albedo +/-
Counter radiation up to +10 %
UV radiation
- in summer
- in winter
 
up to -5 %
up to -30 %
Hours of sunshine
- in summer
- in winter
 
up to -8 %
up to -10 %
Sensitive heat flow up to +50 %
Heat retaining capacity in subsoil and buildings up to +40 %
Air temperature
- annual average
- minimum temperature in winter
- in individual cases
 
about +2 K
about +10 K
about +15 K
Wind
- speed
- gust direction
- gust speed
 
up to -20 %
tremendous variations
increased
Humidity +/-
Fog
- city
- town
 
less
more
Precipitation
- rain
- snow
- dew
 
more (on the lee side)
less
less
Air pollutants
CO, NOx, AVOC1), PAN2)
O3
 
more
less (higher maximum  
Bioclimate
- vegetation season
 
up to 10 days longer
Length of frost period up to -30 %

1)  = man-made hydrocarbons
2)  = ) peroxyacetyl nitrate



Increased pollution of the air due to temperature inversion
Any kind of building has an influence on the various climatic elements. In climatic terms, large built-up areas differ widely from the surrounding region. The main reasons for the development of a separate urban climate are the far-reaching changes in the heat balance and the local wind field. There is also the fact that the air in the city has a higher pollutant concentration due to domestic fuels, traffic, industry and power plants. The development of a typical urban climate depends predominantly on the size of the city, but also on the orography, the development structure and the percentage of open space.

While some climatic elements differ only slightly from one city district to the other (like solar radiation, precipitation), others differ significantly (like temperature, wind conditions) depending on the heat retaining capacity of the construction materials, the sealing of the soil, a modified water balance as well as waste heat. Local differences can be found around buildings, streets and parks.

Further information on the urban climate can be found in the Urban Planning Climate Manual. Climate Booklet for Urban Development


 
 

© City of Stuttgart, Office for Environmental Protection, Section of Urban Climatology