What if a Nuclear Bomb Hit Cairo?

Egypt · Population 9,540,000 · Density 19,000/km²

About Cairo

The capital of Egypt and the largest city in the Arab world; the Greater Cairo region holds over 21 million.

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 Cairo (15 kt)

USA · 1945 · Hiroshima bomb

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)0.43 km~10,952
Severe blast (20 PSI, ~98% fatal)1.18 km~70,227
Moderate blast (5 PSI, ~50% fatal)2.52 km~147,715
Light blast (1 PSI, glass injuries)7.16 km~134,135
3rd-degree thermal burns2.03 km

W76 on Cairo (100 kt)

USA · 1978 · Common SLBM warhead

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)0.91 km~49,962
Severe blast (20 PSI, ~98% fatal)2.20 km~233,976
Moderate blast (5 PSI, ~50% fatal)4.71 km~516,662
Light blast (1 PSI, glass injuries)13.39 km~469,161
3rd-degree thermal burns4.43 km

Castle Bravo on Cairo (15 Mt)

USA · 1954 · Most powerful US nuclear test

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)6.79 km~2,751,139
Severe blast (20 PSI, ~98% fatal)11.51 km~5,001,398
Moderate blast (5 PSI, ~50% fatal)24.60 km~14,106,721
Light blast (1 PSI, glass injuries)69.98 km~12,809,804
3rd-degree thermal burns34.54 km

Tsar Bomba on Cairo (50 Mt)

USSR · 1961 · Largest nuclear weapon ever tested

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)10.99 km~7,208,012
Severe blast (20 PSI, ~98% fatal)17.13 km~9,953,037
Moderate blast (5 PSI, ~50% fatal)36.60 km~31,226,696
Light blast (1 PSI, glass injuries)104.12 km~28,355,837
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 Cairo?

Cairo has approximately 9,540,000 people and an urban density around 19,000 per km². A Hiroshima-yield warhead (15 kt Little Boy) detonated over Cairo would produce a moderate blast radius of about 2.5 km, with an estimated 81,179 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 Cairo from a nuclear strike?

A 100 kt W76 strategic warhead air-burst over Cairo could cause an estimated 800,600 immediate fatalities and around 469,161 additional injured. For comparison, a 50 Mt Tsar Bomba — the largest weapon ever tested — would put roughly 647,081,401 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 Cairo?

For a 100 kt strategic warhead over Cairo: 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 Cairo a likely nuclear target?

This is an educational simulator and does not assess threat probability. Cairo is one of the world's most prominent cities in Africa, 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.