Climate and hazards
Humid foggy plain with muggy summers, milder lakes, Alps with snow from December to April. Winter air quality in the plain is the worst in Italy. Moderate seismic risk only in the Brescia and Garda areas; Seveso and Lambro floods in Milan.
Sections: Seasons · Rainfall · Temperatures · Air quality · Environmental hazards
Plain, lakes, mountains
The Lombard plain has a humid continental climate: grey winters with fog and thermal inversions, hot muggy summers with violent thunderstorms and hail. The lakes (Como, Maggiore, Garda, Iseo) soften the extremes and allow Mediterranean vegetation. The Alps (Valtellina, Valchiavenna, Valcamonica) and pre-Alps have snowy winters: at Livigno, Bormio, Madesimo, Aprica and Ponte di Legno-Tonale the ski season normally runs from December to April.
Air quality
Lombardy is the heart of the Po basin PM10 problem: in 2024, according to SNPA, 80 of the 96 Italian stations above the 35-day exceedance limit were in the Po basin, and the Lombard plain holds the largest share. From October to March the Region activates temporary measures (restrictions on the most polluting vehicles, bans on open burning, heating limits) in plain municipalities; Milan adds Area B and Area C. ARPA Lombardia publishes daily data and forecasts.
Seismicity and floods
Seismic risk is low in most of the region, but the province of Brescia (Garda, Val Trompia, Val Sabbia) and part of the Bergamo area are in zones 2 and 3; the last damaging event was the Salò earthquake of 2004. In Milan the Seveso and Lambro floods periodically hit the northern districts (Niguarda, Isola) despite the retention basins; in Valtellina the reference is the 1987 flood. Summer hail is a real risk for cars and roofs across the plain.
Missing: temp_jan_avg, temp_jul_avg, rain_days_year, air_pm10_days_over_limit
Sources
Updated: 2026-10-14
Updated: 2026-10-14
Updated: 2026-10-14
Updated: 2026-10-14
Reviewed: 10/20/2026 · by piero.avolio · rev. 1 · Period: → 2027-10-31
No questions in the community · Ask the community