Local wind systems, including land and sea breezes, are significant factors influencing temperature distribution over the Kanto Plain. In this study, the diurnal variation patterns of these local wind systems on sunny summer days were classified into five categories based on the divergence field using dense surface observation data. Furthermore, the characteristics of temperature distribution and pressure fields, as well as recent changes in their frequency were examined.

 Each wind category was closely related to the pressure gradient around Japan, revealing differences in temperature distribution based on the wind pattern. In categories with a large northward pressure gradient, a North Pacific subtropical high south of Japan was strong, and the surface wind systems were dominated by southerly winds, causing sea breeze fronts to penetrate quickly. In these categories, notably high daytime temperatures were observed in the eastern Kanto region, where the easterly sea breeze was weaker than average. The frequency of these categories has increased in recent years, likely corresponding to the more frequent appearance of the pressure pattern where the subtropical high extends south of Japan.