The monthly mean minimum and maximum temperatures over the year in Stockholm, Sweden. Show the average temperatures in Stockholm in Celsius Â» Data from nearest weather station: Stockholm, Sweden (0.0 Miles).
The postal service started the use of postal zones for large cities in 1943. By the early 1960s a more general system was needed. On July 1, 1963, ZIP codes were created for the whole country but they were not mandatory. In 1967, these were made mandatory for many types of mail. The system was soon used for all mail.
Using area codes to help efficiently sort post was introduced in 1943. However, by the 1950's a more specific and detailed guide was needed. This is when the United States Postal Service began using the ZIP code (ZIP meaning Zone Improvement Plan).