The city's economy was boosted by the proximity toUdorn Royal Thai Air Force Base during theVietnam War and retains reminders of that time in the form of bars, coffee shops, and hotels. "Udon sort of became likePattaya when theGIs arrived," said a local architect.[3] "Restaurants serving Western cuisine, hotels and nightclubs sprouted up everywhere to meet their needs. It was an extremely busy city back then."[4]
The BBC has reported thatUdon Thani's Royal Air Force Base was the site of a CIAblack site, known to insiders as "Detention Site Green", used to interrogateAbu Zubaydah, Saudi-born Palestinian, believed to be one ofOsama bin Laden's top lieutenants. In December 2014 theUnited States Senate Select Committee on Intelligence (SSCI) published an executive summary of a secret 6,000-page report on CIA techniques. The report alleges that at least eight Thai senior officials knew of the secret site. The site was closed in December 2002.[5]
Udon Thani town municipality (thesaban mueang) with an area of 5.6 km2 (2.2 sq mi) was established on 15 March 1936.[7] On 27 May 1953, the area covered by the municipality was increased to 8.3 km2 (3.2 sq mi).[8] As a result of the town's continuing growth, the total area of the municipality was enlarged for the second time to 47.7 km2 (18.4 sq mi). on 31 December 1993.[9] On 25 September 1995 Udon Thani was upgraded to city municipality (thesaban nakhon),[10] and is divided into 21 sub-districts (tambons), which are further subdivided into 248 villages (mubans). (chumchon), 130,531 people in 60,659 households.[1]
Asia Pacific Potash Corporation (APPC), a wholly owned subsidiary of Italian-Thai Development PLC, owns the concession to theUdon North and Udon Southpotash mines and plans to develop them.[14] Potash deposits in northeast Thailand are believed to contain the world's third-largest—after Canada and Russia—unexploited potash reserves.[15] Potash is one of the main components of agriculturalfertilizer.
Udon Thani has atropical savanna climate (Köppen climate classificationAw). Winters are fairly dry and very warm. Temperatures rise until April, which is hot with the average daily maximum at 36.2 °C (97.2 °F). Themonsoon season runs from late-April through early-October, with heavy rain and somewhat cooler temperatures during the day, although nights remain warm. The range of reliably recorded temperatures in the city is from 2.5 °C (36.5 °F) to 44.1 °C (111.4 °F).
Climate data for Udon Thani (1991–2020, extremes 1951-present)
^ab"รายงานสถิติจำนวนประชากรและบ้านประจำปี พ.ศ.2562" [Statistics, population and house statistics for the year 2019]. Registration Office Department of the Interior, Ministry of the Interior (in Thai). 31 December 2019. Archived fromthe original on 14 June 2019. Retrieved10 March 2020, archiving is not necessary because DOPA provides data from 1993 to future years.{{cite web}}: CS1 maint: postscript (link)
^"Udon Thani".Tourism Authority of Thailand (TAT). Archived fromthe original on 23 June 2012. Retrieved22 August 2015.