Cosmic radiation on flights from Johannesburg (JNB)
O.R. Tambo International Airport, Johannesburg, South Africa. ICAO FAOR, at -26.14°, 28.25°. FlightDose publishes 1 route from here and 1 to here, each direction on its own page.
The one published route from JNB goes to London (JNB → LHR) and receives about 22.3 µSv for a standard flight. A route's dose depends mostly on its hours in the air and how far it runs from the equator (why latitude matters).
Updated
Flying from Johannesburg somewhere else?
The FlightDose app runs CARI-7 for any two airports, with your date, altitude and time in the air.
FlightDose calculates your exact flight.
Free to download on iOS and Android. In-app purchases available.