India Snow Load Map — IS 875 (Part 4):1987
S0 for any Indian city per IS 875 (Part 4):1987. Five zones from None (most of India) to Extreme(above 5,000 m). Drives roof live load, drift load on parapets, and sliding-snow impact on lower roofs.About snow load design
IS 875 (Part 4) gives the basic ground snow load S0. Roof snow load Sr = μ × S0, where μ is the shape coefficient (≤ 0.8 for slopes > 30°, full S0 for flat roofs). Drift load on parapets and sliding-snow on lower roofs add to baseline.
Practical design checks
- None / Low: roof live load 0.75 kN/m² (per IS 875 Part 2) governs over snow.
- Moderate: combine 1.5-2.5 kN/m² snow + drift (parapet height × 0.4 × γ).
- High: design for full S0 on flat roofs; sliding impact on lower roofs.
- Extreme: site-specific snow study + heated drainage.
Cross-references
Source IS / IRC / NBC standards
Related maps
Calculators & tools
Articles & guides
Frequently asked questions
Which Indian cities have significant snow load?
Hill stations above 1,500 m — Shimla, Manali, Mussoorie, Nainital, Darjeeling, Gangtok. Above 3,000 m (Leh, Kargil, Auli) snow load dominates roof design. Plains and peninsular India have S0 = 0.
What is the snow load formula in IS 875?
Roof snow load Sr = μ × S0, where S0 = ground snow load (kN/m² from map), μ = shape coefficient (per IS 875 Part 4 Cl. 5). For flat / low-slope roofs μ = 0.8. For slopes > 60°, μ = 0 (snow slides off). For multi-bay or stepped roofs, drift coefficient adds 0.4-1.0× S0.
Is snow load combined with live load?
Per IS 875 Part 4 Cl. 4.4: snow load + 0.5 × imposed (live) load = combined design load. Take whichever is greater of (snow alone), (live alone), or (snow + 0.5 × live). For occupied roofs, also check snow + occupant load.
Snow load classification is indicative — for projects above 2,500 m elevation, conduct site-specific snow accumulation study (5-day to 30-day cumulative) and apply terrain-specific drift factors per IS 875 Part 4 + relevant snow-research-establishment guidance.