W88 on London

475 kt thermonuclear weapon · United Kingdom · Population 9,002,488 · Density 5,500/km²

About this scenario

This page calculates what would happen if the W88 (USA, 1988) detonated over London (United Kingdom). Modern SLBM warhead.

The capital of the United Kingdom and most populous city in Western Europe, on the River Thames. With an urban-core density of about 5,500 people per km², even a relatively small detonation over the city center would affect a large population.

The W88 delivers 475 kt of explosive yield — 32× more powerful than the Hiroshima bomb. The tables below show calculated effect radii for an air burst (optimized for blast spread) and a surface burst (which produces massive fallout).

Air-burst effects (W88 over London)

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)1.71 km~50,304
Severe blast (20 PSI, ~98% fatal)3.68 km~179,549
Moderate blast (5 PSI, ~50% fatal)7.87 km~418,247
Light blast (1 PSI, glass injuries)22.40 km~379,795
3rd-degree thermal burns8.39 km
2nd-degree thermal burns15.02 km

Estimated total fatalities: ~648,100 · Estimated total affected (inside 1 PSI light-blast radius): ~8,666,936.

Surface-burst effects (with fallout)

A surface burst trades blast spread for radioactive fallout — much smaller blast radii but a large lethal fallout plume drifting downwind. This is what would happen if the W88 struck ground level rather than detonating optimally above London.

Effect zoneRadius (surface burst)
Fireball1.37 km
Severe blast (20 PSI)2.03 km
Moderate blast (5 PSI)4.33 km
Light blast (1 PSI)12.32 km
3rd-degree thermal burns5.03 km
Lethal fallout zone~141.2 km

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See the actual blast zones overlaid on a map of London with population-density-based casualty estimates updated in real time as you move the detonation point.

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W88 on other cities

Other weapons on London

FAQ

What would happen if the W88 detonated over London?

In an air burst over London, the W88 (475 kt) would produce a fireball about 1.71 km in radius. The 5 PSI moderate-blast zone — where most residential buildings collapse — would extend to 7.87 km. Light blast damage and shattered windows would reach 22.40 km. Given London's urban density (~5,500/km²), this scenario yields an estimated 648,100 immediate fatalities and about 379,795 additional injured.

How many people would die in London from a W88 strike?

An air burst of the W88 over London could cause an estimated 648,100 immediate fatalities and 379,795 additional injuries. The fireball alone (radius 1.71 km) would kill approximately 50,304 people; the severe-blast zone (20 PSI, radius 3.68 km) would add 179,549; the moderate-blast zone (5 PSI, radius 7.87 km) would add 418,247 more. Real numbers depend heavily on time of day, sheltering, weather, and altitude of detonation.

What is the blast radius of the W88 on London?

For an air burst over London: fireball 1.71 km, severe blast (20 PSI) 3.68 km, moderate blast (5 PSI) 7.87 km, light blast (1 PSI) 22.40 km. Thermal radiation causes 3rd-degree burns out to 8.39 km. A surface burst would shrink the blast radii by roughly 40 percent but generate massive radioactive fallout extending ~141 km from ground zero.

Is the W88 bigger than the bomb that hit Hiroshima?

The Hiroshima bomb (Little Boy) had a yield of about 15 kilotons. The W88 at 475 kt is 32× more powerful than the Hiroshima bomb.

Casualty math uses London's urban-core density and the scaling laws on the methodology page. See W88 weapon details, the London scenario overview, or browse all scenarios.