Skip to main content

Open Access | Published on October 1, 2026

Seasonality and Meteorological Context of PM₁₀ Exceedance Episodes in Lithuanian Cities, 2019–2025

Sinilga Černulienė
Abstract

Daily PM₁₀ limit-value exceedances remain an urban air-quality concern even where long-term mean concentrations are moderate. This study assessed PM₁₀ exceedance observations in six Lithuanian cities during 2019–2025 and examined their meteorological context. Daily PM₁₀ records were matched with precipitation, wind speed, relative humidity and air temperature. Exceedance observations were defined as station-days with PM₁₀ >50 µg/m³. Seasonality, episode duration, and dry and low-wind conditions were evaluated; station-level patterns, NO₂ concentrations and prevailing wind direction were additionally analysed in Vilnius and Kaunas. Exceedances were episodic and most frequent in spring in all cities. They were generally characterised by lower precipitation, lower relative humidity and, in most cities, lower wind speed than non-exceedance observations. Most occurred when daily precipitation was <1 mm. At the Vilnius and Kaunas stations, PM₁₀ was negatively correlated with precipitation, wind speed and relative humidity, while NO₂ concentrations were higher during exceedances. Higher exceedance rates were also observed under easterly and south-easterly winds. The findings associate PM₁₀ episodes with dry conditions and limited dispersion; their spring predominance is consistent with conditions favourable to road-dust resuspension, although individual source contributions were not directly quantified.

Graphical abstract
Download graphical abstract
Keywords
air quality, road dust, Precipitation, Wind Speed, relative humidity, non-exhaust emissionsc