What if a Nuclear Bomb Hit Singapore?

Singapore · Population 5,900,000 · Density 8,300/km²

About Singapore

An island city-state and major global financial hub at the southern tip of the Malay Peninsula.

Below are four scenario calculations using historical and modern nuclear weapons. Each row shows the radius of an effect zone in kilometers and a rough order-of-magnitude estimate of people inside that zone, derived from the city's urban population density. Numbers are educational approximations — see the methodology page for the underlying formulas.

Little Boy on Singapore (15 kt)

USA · 1945 · Hiroshima bomb

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)0.43 km~4,785
Severe blast (20 PSI, ~98% fatal)1.18 km~30,677
Moderate blast (5 PSI, ~50% fatal)2.52 km~64,528
Light blast (1 PSI, glass injuries)7.16 km~58,596
3rd-degree thermal burns2.03 km

W76 on Singapore (100 kt)

USA · 1978 · Common SLBM warhead

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)0.91 km~21,825
Severe blast (20 PSI, ~98% fatal)2.20 km~102,211
Moderate blast (5 PSI, ~50% fatal)4.71 km~225,699
Light blast (1 PSI, glass injuries)13.39 km~204,950
3rd-degree thermal burns4.43 km

Castle Bravo on Singapore (15 Mt)

USA · 1954 · Most powerful US nuclear test

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)6.79 km~1,201,813
Severe blast (20 PSI, ~98% fatal)11.51 km~2,184,822
Moderate blast (5 PSI, ~50% fatal)24.60 km~6,162,409
Light blast (1 PSI, glass injuries)69.98 km~5,595,862
3rd-degree thermal burns34.54 km

Tsar Bomba on Singapore (50 Mt)

USSR · 1961 · Largest nuclear weapon ever tested

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)10.99 km~3,148,763
Severe blast (20 PSI, ~98% fatal)17.13 km~4,347,906
Moderate blast (5 PSI, ~50% fatal)36.60 km~13,641,135
Light blast (1 PSI, glass injuries)104.12 km~12,387,023
3rd-degree thermal burns56.58 km

Limitations

These estimates assume an idealized air burst over the city center, uniform population density, and no advance warning or sheltering. Real-world casualties would depend on:

  • Time of day (population is concentrated downtown during business hours)
  • Sheltering and basements (subway systems can reduce casualties significantly)
  • Building construction (reinforced steel/concrete vs. wood-frame)
  • Weather and atmospheric conditions
  • Detonation altitude (air burst vs. surface burst)
  • Subsequent fallout and infrastructure collapse

Other City Scenarios

FAQ

What would happen if a nuclear bomb hit Singapore?

Singapore has approximately 5,900,000 people and an urban density around 8,300 per km². A Hiroshima-yield warhead (15 kt Little Boy) detonated over Singapore would produce a moderate blast radius of about 2.5 km, with an estimated 35,462 immediate fatalities in the severe-blast zone. A modern strategic warhead (W76, 100 kt) would extend the moderate-damage zone to roughly 4.7 km with thermal burns reaching 4.4 km. Run the interactive simulator above to see the exact zones overlaid on the map.

How many people would die in Singapore from a nuclear strike?

A 100 kt W76 strategic warhead air-burst over Singapore could cause an estimated 349,735 immediate fatalities and around 204,950 additional injured. For comparison, a 50 Mt Tsar Bomba — the largest weapon ever tested — would put roughly 282,672,402 people inside the 1 PSI light-blast zone alone. Real casualties depend strongly on time of day, sheltering, weather, and altitude of detonation.

What is the blast radius of a nuclear bomb over Singapore?

For a 100 kt strategic warhead over Singapore: fireball radius 0.91 km, severe blast (20 PSI) 2.20 km, moderate blast (5 PSI) 4.71 km, light blast (1 PSI) 13.39 km, third-degree thermal burns 4.43 km. Larger yields scale these radii roughly as the cube root of yield for blast and the 0.41 power for thermal effects.

Is Singapore a likely nuclear target?

This is an educational simulator and does not assess threat probability. Singapore is one of the world's most prominent cities in Asia, which is why we feature it as a scenario. The purpose of these visualizations is to convey the humanitarian scale of nuclear weapons — not to make any operational claim.

See also: full Weapons Database (45+ entries) · Scientific methodology · Data sources.