{"icao":"KHLN","name":"Helena Regional Airport","lat":46.6068,"lon":-111.983,"country":"US","tz":"America/Denver","updated":"2026-09-04T14:25Z","window":{"start":"2016-01-01","through":"2026-08-15"},"climatology":{"subCat1HoursPerYear":29,"bandDefinition":"visibility < ~800 m OR ceiling < 200 ft","fogSeasonPeakMonths":["January","December"],"monthlyHours":[10,1,4,1,1,0,0,0,1,2,2,6],"medianEventHours":1,"season":{"summary":"Fog season is January, March, December, peaking in January; fog is mostly a 7 AM\u20139 AM phenomenon; typically thinning out by noon; a typical event lasts about 1 hour (local time, 10-year average).","months":["January","March","December"],"timeOfDay":"7 AM\u20139 AM","typicallyClearsBy":"noon"}},"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 1 hour of dense fog here."},"links":{"page":"https://fogatlas.org/fog/khln/","liveForecastApi":"https://fogatlas.org/api/forecast","liveObservationsApi":"https://fogatlas.org/api/metar?ids=KHLN","hourlyClimatologyDetail":"https://fogatlas.org/data/detail/KHLN.json","verification":"https://fogatlas.org/fog/scorecard/","methodology":"https://fogatlas.org/#methodology"}}