{"icao":"KRFD","name":"Chicago Rockford International Airport","lat":42.1954,"lon":-89.0972,"country":"US","tz":"America/Chicago","updated":"2026-09-04T14:25Z","window":{"start":"2016-01-01","through":"2026-08-15"},"climatology":{"subCat1HoursPerYear":37,"bandDefinition":"visibility < ~800 m OR ceiling < 200 ft","fogSeasonPeakMonths":["December","January"],"monthlyHours":[8,5,3,1,1,1,1,2,2,1,4,9],"medianEventHours":2,"season":{"summary":"Fog season runs November through March, peaking in December; fog is mostly a 4 AM\u20139 AM phenomenon; typically thinning out by 11 AM; a typical event lasts about 2 hours (local time, 10-year average).","months":["January","February","March","November","December"],"timeOfDay":"4 AM\u20139 AM","typicallyClearsBy":"11 AM"}},"forecast":{"covered":true,"public":true,"cycle":"2026-09-04T13:00:00Z","peakPct":9,"peakAtLocal":"2026-09-05T05:00:00-05:00","wording":"No, fog is unlikely in the next 36 hours \u2014 the calibrated forecast peaks at just 9%. September typically brings about 2 hours of dense fog here."},"links":{"page":"https://fogatlas.org/fog/krfd/","liveForecastApi":"https://fogatlas.org/api/forecast","liveObservationsApi":"https://fogatlas.org/api/metar?ids=KRFD","hourlyClimatologyDetail":"https://fogatlas.org/data/detail/KRFD.json","verification":"https://fogatlas.org/fog/scorecard/","methodology":"https://fogatlas.org/#methodology"}}