Sleet

What is Sleet?

Sleet is a form of precipitation consisting of small translucent ice pellets that bounce when they hit the ground. The pellets are typically 2-5 mm in diameter and formed through a specific atmospheric process involving freezing, melting and refreezing.

It is meteorologically distinct from:

• Snow — soft white ice crystals that stick together
• Hail — larger, harder ice formed in summer thunderstorms (typically 5-50+ mm)
• Freezing rain — supercooled liquid that freezes on contact with surfaces
• Graupel — soft, opaque white pellets (rimed snowflakes)

In South Asia, sleet is uncommon but not rare at intermediate elevations during winter Western Disturbances. It is the transitional form of precipitation between full snow (at higher elevations) and full rain (at lower elevations).

How sleet forms

Sleet requires a specific vertical temperature profile:

1. Snow forms in cold upper clouds (typical for winter)
2. Snowflakes fall through a warm layer (above 0°C) — partially or fully melt
3. Melted droplets enter a sub-freezing layer near the ground
4. They refreeze into ice pellets before reaching the surface
5. Pellets hit the ground and bounce — sleet has arrived

The warm middle layer is typically 100-1000 m thick. If the warm layer is too thick, the snow melts completely and falls as plain rain. If the cold lower layer is too thin, the partially-melted snow can’t refreeze and falls as freezing rain.

This narrow window of vertical temperatures explains why sleet is comparatively rare — but the conditions DO occur frequently in winter Himalayan storms.

Where sleet occurs in South Asia

Most common:

• Kashmir Valley (Srinagar, Pulwama, Anantnag) — intermediate elevations during WD passage
• Northern Pakistan (Murree, Kohat, Bannu) — winter transition events
• Himachal foothills (Dharamshala, Palampur, Kangra valley) — moderate elevations
• Uttarakhand foothills (Dehradun, Mussoorie outskirts) — occasional
• Sikkim, Northeast India hill stations (Gangtok, Shillong) — periodic

Rare but recorded:

• Delhi NCR — extremely rare; recorded in some severe cold events
• Chandigarh, Amritsar — during exceptional WD events
• Bihar foothills (Kishanganj) — rare

Not seen:

• Tropical south India, Bangladesh delta, Sri Lanka, Maldives — too warm

Sleet vs other ice precipitation

The differences matter operationally:

• Sleet doesn’t accumulate as fast as snow but creates icy surfaces
• Freezing rain is the most dangerous for power lines and roads
• Hail can damage crops, vehicles, roofs
• Graupel rarely causes major problems

Sleet hazards

For South Asian travelers and residents:

Roads:

• Sleet quickly creates slippery layers on roads
• Mountain roads (Manali-Leh, Srinagar-Jammu, Karakoram Highway) become hazardous
• Brake distance increases 2-3× compared to dry pavement

Walking:

• Sidewalks and footpaths become slick
• Falls and injuries common in Kashmir and HP during sleet events
• Wear non-slip footwear

Power and infrastructure:

• Sleet usually doesn’t accumulate enough to break power lines (unlike heavy snow or freezing rain)
• But sleet + sustained cold can lead to broken icicles falling from rooftops/eaves

Agriculture:

• Sleet can damage tender winter crops if accumulation occurs
• Mango orchards in Bihar/UP foothills vulnerable to late winter sleet
• Greenhouse covers can collapse under heavy sleet + snow combination

Aviation:

• Sleet doesn’t typically cause direct flight problems
• But the meteorological conditions producing sleet often include icing risk at altitude
• Pre-frontal turbulence common

Sleet forecasting

Sleet is difficult to forecast because it depends on a narrow window of vertical temperatures. Models can predict the overall storm and rough precipitation type but often miss the exact altitude where rain transitions to sleet to snow.

Best practice:

• Monitor weather forecasts ahead of winter storm
• Watch for “wintry mix” or “mixed precipitation” in forecasts
• Be prepared for transitions during the storm
• Carry chains/winter tyres for mountain travel

How to prepare for sleet

If sleet is forecast:

1. Stock supplies — food, water, blankets for 24-48 hours
2. Avoid unnecessary travel — especially on hilly roads
3. Carry winter gear if travel is essential
4. Keep emergency contacts — utility, road clearance, medical
5. Charge devices in case of power disruption
6. Inspect property — secure loose items that could fall under ice weight
7. Pets and outdoor animals — bring them in or provide warm shelter

Frequently asked questions

Is sleet the same as hail? No. Hail forms in summer thunderstorms via repeated up-and-down cycling in cumulonimbus clouds — larger, harder, often layered. Sleet forms in winter storms when snow partially melts then refreezes — small, translucent pellets.

Does sleet melt quickly? On warm ground (above 0°C), yes — within minutes to an hour. On cold ground (below 0°C), sleet can persist for hours or days, creating icy patches even after the storm.

Why is sleet less common than snow or rain? Sleet requires a specific vertical temperature profile — cold above, warm middle, cold near ground. This three-layer setup is harder to achieve than uniformly cold (snow) or uniformly warm (rain) conditions.

Can sleet damage cars? Generally no — pellets are small and bounce. But the freezing surface left behind can damage tyres at speed and cause accidents. Severe sleet combined with freezing rain can damage windshields and break car windows.

Where can I check winter precipitation forecasts for Himalayan regions? Mausam Online displays precipitation forecasts on every city page. For winter precip in Himalayan regions, see Srinagar, Manali, Shimla, Skardu, Murree, Gangtok.

Related terms

• Snow
• Precipitation
• Frost
• Western Disturbance
• Hail