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.
Modern two-letter abbreviated codes for the states and territories originated when the Post Office introduced ZIP codes in 1963. The purpose was to make room for ZIP codes in the address, rather than to standardize state abbreviations per se. Since 1963, only one state abbreviation has changed.