Cloud Types and Their Meanings
High Clouds (above ~20,000 ft / 6,000 m)
Cirrus: Wispy, feathery streaks; fair weather now, change approaching.
Cirrostratus: Thin, veil-like; can create halos, often means rain/snow within 12–24 hours.
Cirrocumulus: Small, patchy, rippling; 'Mackerel sky,' fair but cold, may precede storms.
Mid-Level Clouds (6,500–20,000 ft / 2,000–6,000 m)
Altostratus: Gray, sheet-like, sun dim; usually precedes steady rain or snow.
Altocumulus: White/gray, lumpy; can signal thunderstorms later in the day if humid/warm.
Low Clouds (surface to 6,500 ft / 2,000 m)
Stratus: Uniform, gray, flat; may bring drizzle or light snow.
Stratocumulus: Low, lumpy, with breaks of sunlight; fair weather or light precipitation.
Nimbostratus: Dark, thick, covering the sky; steady rain or snow.
Vertical Clouds (growing from low to high)
Cumulus: Puffy, cotton-like; fair weather unless they grow larger.
Cumulonimbus: Towering, anvil-shaped; thunderstorms, heavy rain, hail, tornadoes.
High Clouds (above ~20,000 ft / 6,000 m)
Cirrus: Wispy, feathery streaks; fair weather now, change approaching.
Cirrostratus: Thin, veil-like; can create halos, often means rain/snow within 12–24 hours.
Cirrocumulus: Small, patchy, rippling; 'Mackerel sky,' fair but cold, may precede storms.
Mid-Level Clouds (6,500–20,000 ft / 2,000–6,000 m)
Altostratus: Gray, sheet-like, sun dim; usually precedes steady rain or snow.
Altocumulus: White/gray, lumpy; can signal thunderstorms later in the day if humid/warm.
Low Clouds (surface to 6,500 ft / 2,000 m)
Stratus: Uniform, gray, flat; may bring drizzle or light snow.
Stratocumulus: Low, lumpy, with breaks of sunlight; fair weather or light precipitation.
Nimbostratus: Dark, thick, covering the sky; steady rain or snow.
Vertical Clouds (growing from low to high)
Cumulus: Puffy, cotton-like; fair weather unless they grow larger.
Cumulonimbus: Towering, anvil-shaped; thunderstorms, heavy rain, hail, tornadoes.
