The sea-land breeze (SLB) occurs regularly in coastal areas and influences the local climate atmospheric environment. Fifteen-year observations (2005–2019) from urban, coastal, marine stations were collected to examine trend number of SLB days (SLBD) Tianjin, a megacity China. SLBD Tianjin generally showed decreasing with an annual average decline rate 3.89%. land speed decreased by 0.20 m·s−1 ...