The philosophy, background, and details of high-resolution urban observation network to meet the need of reducing damages caused by extreme weather phenomena such as heavy rain/snow fall, strong wind, heat/cold waves, or road ice in the Seoul Metropolitan Area (SMA), Korea (UMS-Seoul), is introduced. Two case studies demonstrate that the observed data have a great potential to help to understand the boundary-layer structures more deepl and provide useful meteorological information in the SMA.