{"icao":"KMDH","name":"Southern Illinois Airport","lat":37.7781,"lon":-89.252,"country":"US","tz":"America/Chicago","updated":"2026-09-04T14:25Z","window":{"start":"2016-01-01","through":"2026-08-15"},"climatology":{"subCat1HoursPerYear":64,"bandDefinition":"visibility < ~800 m OR ceiling < 200 ft","fogSeasonPeakMonths":["September","August"],"monthlyHours":[5,3,3,4,1,1,4,10,15,8,6,5],"medianEventHours":1,"season":{"summary":"Fog season is January, April, July, August, September, October, November, December, peaking in September; fog is mostly a 1 AM\u20136 AM phenomenon; typically thinning out by 8 AM; a typical event lasts about 1 hour (local time, 10-year average).","months":["January","April","July","August","September","October","November","December"],"timeOfDay":"1 AM\u20136 AM","typicallyClearsBy":"8 AM"}},"forecast":{"covered":true,"public":false,"cycle":"2026-09-04T13:00:00Z","guidanceSignal":false,"wording":"No fog signal in NWS guidance for the next 48 hours. September typically brings about 15 hours of dense fog here."},"links":{"page":"https://fogatlas.org/fog/kmdh/","liveForecastApi":"https://fogatlas.org/api/forecast","liveObservationsApi":"https://fogatlas.org/api/metar?ids=KMDH","hourlyClimatologyDetail":"https://fogatlas.org/data/detail/KMDH.json","verification":"https://fogatlas.org/fog/scorecard/","methodology":"https://fogatlas.org/#methodology"}}