Abstract
We have analyzed air temperature observations in Prague, the Czech Republic, with an emphasis on the properties and dynamics of its urban heat island (UHI). Warming of the city has become apparent over the last 53 years (1961-2013), no matter whether maximum, minimum or mean temperatures are being considered.
Linear trends reach up to +0.6 oC/decade for some months and are very often statistically significant. Monthly temperatures have increased up to +1.5 oC when comparing the periods, 1961-1990 and 1991-2013.
Warming is the strongest in the city centre and indirectly points out the UHI amplification. The reoccurrence of extremely hot days and nights is growing statistically significantly in the city centre and faster than at suburban stations.
The assessment of the UHI is based on a comparison of air temperatures at the Klementinum urban station and three rural stations. From April to September, the UHI intensity for monthly minimum temperature exceeds 2 oC and has increased by 0.5-0.7 oC in the last 23 years.
Monthly UHI intensities derived from mean and maximum temperatures and their changes in time are generally smaller (or even negative from March to October for maximum temperature).