{"icao":"EFSI","name":"Sein\u00e4joki Airport","lat":62.6921,"lon":22.8323,"country":"FI","tz":"Europe/Helsinki","updated":"2026-09-04T14:25Z","window":{"start":"2016-01-01","through":"2026-08-15"},"climatology":{"subCat1HoursPerYear":250,"bandDefinition":"visibility < ~800 m OR ceiling < 200 ft","fogSeasonPeakMonths":["September","October"],"monthlyHours":[26,19,14,11,10,9,17,31,36,31,30,21],"medianEventHours":1,"season":{"summary":"Fog season is year-round, peaking in September; fog is mostly a 11 PM\u20138 AM phenomenon; typically thinning out by 11 AM; a typical event lasts about 1 hour (local time, 10-year average).","months":["January","February","March","April","May","June","July","August","September","October","November","December"],"timeOfDay":"11 PM\u20138 AM","typicallyClearsBy":"11 AM"}},"forecast":{"covered":false,"public":false,"wording":"No fog forecast feed exists for this station. September typically brings about 36 hours of dense fog here (10-year average)."},"links":{"page":"https://fogatlas.org/fog/efsi/","liveForecastApi":"https://fogatlas.org/api/forecast","liveObservationsApi":"https://fogatlas.org/api/metar?ids=EFSI","hourlyClimatologyDetail":"https://fogatlas.org/data/detail/EFSI.json","verification":"https://fogatlas.org/fog/scorecard/","methodology":"https://fogatlas.org/#methodology"}}