{"icao":"KPWK","name":"Chicago Executive Airport","lat":42.1142,"lon":-87.9015,"country":"US","tz":"America/Chicago","updated":"2026-09-04T14:25Z","window":{"start":"2016-01-01","through":"2026-08-15"},"climatology":{"subCat1HoursPerYear":20,"bandDefinition":"visibility < ~800 m OR ceiling < 200 ft","fogSeasonPeakMonths":["January","December"],"monthlyHours":[7,1,1,1,1,0,0,1,1,0,1,4],"medianEventHours":1,"season":{"summary":"Fog season runs December through January, peaking in January; fog is mostly a 8 PM\u20135 AM phenomenon; typically thinning out by 10 AM; a typical event lasts about 1 hour (local time, 10-year average).","months":["January","December"],"timeOfDay":"8 PM\u20135 AM","typicallyClearsBy":"10 AM"}},"forecast":{"covered":true,"public":true,"cycle":"2026-09-04T13:00:00Z","peakPct":3,"peakAtLocal":"2026-09-05T06:00:00-05:00","wording":"No, fog is unlikely in the next 36 hours \u2014 the calibrated forecast peaks at just 3%. September typically brings about 1 hour of dense fog here."},"links":{"page":"https://fogatlas.org/fog/kpwk/","liveForecastApi":"https://fogatlas.org/api/forecast","liveObservationsApi":"https://fogatlas.org/api/metar?ids=KPWK","hourlyClimatologyDetail":"https://fogatlas.org/data/detail/KPWK.json","verification":"https://fogatlas.org/fog/scorecard/","methodology":"https://fogatlas.org/#methodology"}}