METAR weather code reference for HZ (Haze)
Fine dry particles of dust, salt, or other matter suspended in the atmosphere that give the sky a characteristic opalescent appearance. Unlike mist, haze particles are not water-based. Haze reduces visibility and is most common in warm, dry conditions. It can persist for days under stagnant high pressure systems.
Here are common ways HZ appears in real METAR observations:
HZHZ FEW250HZ SCT050These METAR codes are commonly seen alongside HZ or describe related weather phenomena:
Small particles suspended in the air from combustion, such as wildfires, industrial activity, or agricultural burning. Smoke can dramatically reduce visibility across large areas and may persist for weeks during wildfire season. It can reach very high altitudes and affect flight operations far from the source.
Fine particles of earth or other matter raised from the ground by wind and suspended in the atmosphere. Widespread dust reduces visibility and is most commonly reported in arid regions. Dust events can cause significant restrictions to visibility and affect engine performance.
Microscopic water droplets or wet hygroscopic particles suspended in the atmosphere, reducing visibility to between 5/8 of a mile and 6 miles. The abbreviation comes from the French word 'brume.' Affectionately known among pilots as 'baby rain,' BR is one of the most frequently reported obscurations and often accompanies low ceilings and stable air.