With the development of the low-altitude economy, urban low-altitude flight activities have become increasingly dependent on meteorological conditions. Systematically identifying the flight meteorological potential under different weather conditions is of great significance for operational organization and airspace planning. This paper constructs an evaluation index system for low-altitude flight meteorological potential, consisting of availability, failure frequency, average failure duration, and maximum continuous availability. Based on ERA5 reanalysis data, near-surface meteorological data for 328 typical cities worldwide were obtained, and the spatiotemporal differences in urban low-altitude flight meteorological potential were systematically analyzed from the perspectives of climate zones, regions (continents), and seasons. The study employs methods such as grouped statistics, Kruskal–Wallis significance tests, multi-class regression, and effect size decomposition to quantitatively identify the relative contributions of multiple factors to urban low-altitude flight availability and to construct a forecasting framework for availability under climate zone and seasonal combinations. The results indicate that, overall, the meteorological potential for low-altitude urban flights is high globally, but there are significant differences across latitudes, regions, and seasons: tropical and some subtropical cities exhibit the highest availability, the fewest failure events, and the shortest durations, whereas temperate cities, affected by frontal systems and mid-to-high latitude weather disturbances, have relatively lower availability. Seasonally, the trend generally follows the pattern of 'least favorable in winter, most favorable in summer.' Multi-class regression and effect size analysis show that climate zones (partial η² = 0.166) and seasonality (partial η² = 0.151) are the dominant factors affecting availability, whereas the independent effect of region (continent) is relatively weak (partial η²= 0.035). The predictive heatmaps for combinations of climate zones and seasons further reveal the interactive structure through which large-scale climatic backgrounds and seasonal rhythms jointly shape the meteorological potential for urban low-altitude flight. The proposed global assessment framework and multi-factor analysis methods provide quantitative support for urban airspace planning, operational strategy formulation, and UAM (Urban Air Mobility) airworthiness zoning.