Human　activity　plays　a　crucial　role　in　influencing　PM2.5　concentration　and　can　be　assessed　through　nighttime　light　remote　sensing.　Therefore,　it　is　important　to　investigate　whether　the　nighttime　light　brightness　can　enhance　the　accuracy　of　PM2.5　simulation　in　different　stages.　Utilizing　PM2.5　mobile　monitoring　data,　this　study　introduces　nighttime　lighting　brightness　as　an　additional　factor　in　the　PM2.5　simulation　model　across　various　time　periods.　It　compares　the　differences　in　simulation　accuracy,　explores　the　impact　of　nocturnal　human　activities　on　PM2.5　concentrations　at　different　periods　of　the　following　day,　and　analyzes　the　spatial　and　temporal　pollution　pattern　of　PM2.5　in　urban　functional　areas.　The　results　show　that　(1)　the　incorporation　of　nighttime　lighting　brightness　effectively　enhances　the　model＇s　accuracy　(R2),　with　an　improvement　ranging　from　0.04　to　0.12　for　different　periods　ranges.　(2)　the　model＇s　accuracy　improves　more　prominently　during　8:00–12:00　on　the　following　day,　and　less　so　during　12:00–18:00,　as　the　PM2.5　from　human　activities　during　the　night　experiences　a　strong　aggregation　effect　in　the　morning　of　the　next　day,　with　the　effect　on　PM2.5　concentration　declining　after　diffusion　until　the　afternoon.　(3)　PM2.5　is　primarily　concentrated　in　urban　functional　areas　including　construction　sites,　roads,　and　industrial　areas　during　each　period.　But　in　the　period　of　8:00–12:00,　there　is　a　significant　level　of　PM2.5　pollution　observed　in　commercial　and　residential　areas,　due　to　the　human　activities　that　occurred　the　previous　night.　©　2024　Elsevier　B.V.