May 1956

Tuesday 01:

The polio vaccine developed by Jonas Salk is made available to the public.

Thursday 03:

The judo World Championships are first held.

Wednesday 09:

First ascent of Manaslu, the world's eighth-highest mountain.

Monday 21:

Nuclear testing: In the Pacific Ocean, Bikini Atoll is nearly obliterated by the first airborne explosion of a hydrogen bomb.

Thursday 24:

In Lugano, Switzerland, Lys Assia wins the first Eurovision Song Contest for Switzerland singing "Refrain".