Nuclear Impact Analysis · Brazil

Is São Paulo safe from a nuclear strike?

We modelled the most plausible strategic targets around São Paulo and simulated blast, thermal, radiation and fallout effects against its 22,400,000 metro residents.

37/100
HIGH RISK

São Paulo city centre sits 2.6 km from São Paulo (Paulista), the most plausible strategic target in the area (low targeting confidence). Modelled strike: 300 kt airburst.

Estimated survival chance at city centre: 25% · Estimated metro fatalities: 855.9K, injuries: 1M

Run the interactive simulation for São Paulo →

What a strike on São Paulo (Paulista) would mean

A 300 kt detonation produces a fireball 646 m across in radius. Reinforced concrete fails out to 2.3 km (20 psi). Most residential buildings collapse within 4.6 km (5 psi), and windows shatter dangerously out to 10.4 km (1 psi). Anyone in line of sight within 6.9 km suffers third-degree burns from the thermal pulse.

An airburst maximises blast damage but produces minimal local fallout, so for São Paulo the dominant risks are blast and thermal effects rather than radiation.

Most plausible targets near São Paulo

TargetTypeDistanceAssumed yieldConfidence
São Paulo (Paulista)city3 km300 ktlow
Buenos Airescity1675 km150 ktlow
Lagoscity6374 km100 ktlow
Kings Bay Naval Base (SSBN)military7098 km800 kthigh
Port of Savannahport7195 km150 ktmedium

Key blast radii (300 kt airburst)

EffectRadiusWhat happens
Fireball646 mComplete vaporisation
20 psi blast2.3 kmHardened structures destroyed, ~100% fatalities
5 psi blast4.6 kmMost buildings collapse, widespread fatalities
3rd-degree burns6.9 kmFull-thickness burns to exposed skin
500 rem radiation2.4 kmLethal dose without medical care
1 psi blast10.4 kmWindow breakage, light damage, glass injuries

How São Paulo can prepare

With a population density of 7,400 people/km², São Paulo's outcome would hinge on the first hour. The guidance is identical everywhere: get inside, stay inside, stay tuned. A basement or the core of a large concrete building cuts fallout exposure by a factor of 10 or more, and radiation decays fast — dose rates fall ~90% within the first 7 hours and ~99% within two days.

Check your exact address in São Paulo →
Model disclaimer: These are research-grade estimates from open scaling laws (Glasstone & Dolan, 1977), not predictions. Actual outcomes depend on burst height, weapon choice, weather, terrain and sheltering. In any real emergency follow official civil-defence guidance.

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