Editing Xi'an (section)

==Climate==

Xi'an has a [[temperateness|temperate]] climate that is influenced by the [[East Asian monsoon]], classified under the [[Köppen climate classification]] as a borderline [[humid subtropical climate|humid subtropical]] and [[humid continental climate]] (''Cwa/Dwa''). The Wei River valley is characterized by hot, [[Humidity|humid]] summers, cold, dry winters, and dry springs and autumns. Most of the annual [[Precipitation (meteorology)|precipitation]] is delivered from July to late October. Snow occasionally falls in winter but rarely settles for long. [[Dust storm]]s often occur during March and April as the city rapidly warms up. Summer months also experience frequent but short [[thunderstorm]]s. The monthly 24-hour average temperature ranges from around the freezing mark in January to {{convert|27.0|°C|1}} in July, with an annual mean of {{convert|14.08|°C|1}}. Extremes since 1951 have ranged from {{convert|−20.6|°C|0}} on January 11, 1955, to {{convert|41.8|°C|0}} on June 21, 1998 and July 24, 2017. A highest record of {{convert|42.9|°C|0}} was registered in another station on June 17, 2006.<ref>{{cite web |url=http://cdc.cma.gov.cn/dataSetLogger.do?changeFlag%3DdataLogger |title=无标题文档 |access-date=2013-02-18 |url-status=dead |archive-url=https://web.archive.org/web/20130318113757/http://cdc.cma.gov.cn/dataSetLogger.do?changeFlag=dataLogger |archive-date=2013-03-18}}</ref><ref name = Mherrera/> An unofficial record low of {{convert|-25.0|°C|0}} was also recorded in January 1930, but at another weather station in the northern suburbs of the city.<ref>{{Cite web |title=中国各地城市的历史最低气温 |url=https://weibo.com/ttarticle/p/show?id=2309404203050792315805 |access-date=2024-09-17 |website=weibo.com}}</ref>

{{Weather box
|width = auto
|location = Xi'an ([[Chang'an District, Xi'an|Chang'an District]]), elevation {{convert|445|m|ft|abbr=on}}, (1991–2020 normals, extremes 1951–2013)

|metric first = Y
|single line  = Y
|collapsed    = Y

|Jan high C = 5.0
|Feb high C = 9.3
|Mar high C = 15.5
|Apr high C = 22.1
|May high C = 26.9
|Jun high C = 31.7
|Jul high C = 32.8
|Aug high C = 30.7
|Sep high C = 25.4
|Oct high C = 19.3
|Nov high C = 12.6
|Dec high C = 6.6
|Jan mean C = -0.5
|Feb mean C = 3.3
|Mar mean C = 9.0
|Apr mean C = 15.1
|May mean C = 20.0
|Jun mean C = 24.9
|Jul mean C = 26.9
|Aug mean C = 25.0
|Sep mean C = 19.9
|Oct mean C = 13.7
|Nov mean C = 6.9
|Dec mean C = 1.1
|year mean C = 	
|Jan low C = -4.4
|Feb low C = -1.1
|Mar low C = 3.9
|Apr low C = 9.2
|May low C = 13.9
|Jun low C = 18.7
|Jul low C = 21.7
|Aug low C = 20.5
|Sep low C = 15.8
|Oct low C = 9.8
|Nov low C = 2.8
|Dec low C = -2.7

|Jan record high C = 17.0
|Feb record high C = 24.1
|Mar record high C = 31.3
|Apr record high C = 34.9
|May record high C = 38.6
|Jun record high C = 41.8
|Jul record high C = 41.0
|Aug record high C = 40.0
|Sep record high C = 38.5
|Oct record high C = 34.1
|Nov record high C = 24.5
|Dec record high C = 21.6
|year record high C= 41.8
|Jan record low C = −20.6
|Feb record low C = −18.7
|Mar record low C =  −7.6
|Apr record low C =  −4.0
|May record low C =  3.5
|Jun record low C =  9.2
|Jul record low C =  15.1
|Aug record low C =  12.1
|Sep record low C =  4.8
|Oct record low C = −1.9
|Nov record low C = −16.8
|Dec record low C = −19.3
|year record low C= −20.6
|precipitation colour = green	
|Jan precipitation mm = 8.8
|Feb precipitation mm = 13.3
|Mar precipitation mm = 28.4
|Apr precipitation mm = 49.6
|May precipitation mm = 68.0
|Jun precipitation mm = 85.6
|Jul precipitation mm = 103.8
|Aug precipitation mm = 96.7
|Sep precipitation mm = 117.2
|Oct precipitation mm = 66.6
|Nov precipitation mm = 27.9
|Dec precipitation mm = 6.5
|unit precipitation days = 0.1 mm	
|Jan precipitation days = 4.0
|Feb precipitation days = 4.7
|Mar precipitation days = 7.2
|Apr precipitation days = 7.8
|May precipitation days = 9.8
|Jun precipitation days = 9.1
|Jul precipitation days = 10.8
|Aug precipitation days = 10.4
|Sep precipitation days = 12.3
|Oct precipitation days = 11.0
|Nov precipitation days = 6.1
|Dec precipitation days = 3.5
|year precipitation days = 	
|Jan humidity = 67
|Feb humidity = 67
|Mar humidity = 65
|Apr humidity = 66
|May humidity = 66
|Jun humidity = 63
|Jul humidity = 70
|Aug humidity = 76
|Sep humidity = 80
|Oct humidity = 80
|Nov humidity = 77
|Dec humidity = 69
|Jan sun = 120.2
|Feb sun = 121.4
|Mar sun = 160.2
|Apr sun = 185.1
|May sun = 200.1
|Jun sun = 201.2
|Jul sun = 209.3
|Aug sun = 176.1
|Sep sun = 135.2
|Oct sun = 119.8
|Nov sun = 120.6
|Dec sun = 121.7
|year sun = 	
| Jan percentsun = 38
| Feb percentsun = 39
| Mar percentsun = 43
| Apr percentsun = 47
| May percentsun = 46
| Jun percentsun = 47
| Jul percentsun = 48
| Aug percentsun = 43
| Sep percentsun = 37
| Oct percentsun = 35
| Nov percentsun = 39
| Dec percentsun = 40
| year percentsun =	
|Jan snow days = 4.7
|Feb snow days = 3.7
|Mar snow days = 1.3
|Apr snow days = 0.1
|May snow days = 0.1
|Jun snow days = 0
|Jul snow days = 0
|Aug snow days = 0
|Sep snow days = 0
|Oct snow days = 0
|Nov snow days = 1.3
|Dec snow days = 2.8
|year snow days = 	
|source 1 = China Meteorological Administration<ref name="cma graphical">{{cite web |url=http://data.cma.cn/data/weatherBk.html |script-title=zh:中国气象数据网 – WeatherBk Data |publisher=[[China Meteorological Administration]] |language=zh-hans |access-date=3 July 2023 |archive-date=September 5, 2018 |archive-url=https://web.archive.org/web/20180905194950/http://data.cma.cn/data/weatherBk.html |url-status=live }}</ref><ref>{{cite web
|url=https://experience.arcgis.com/template/e724038fda394e9d9b7921f10fd1aa55/page/%E7%BA%AF%E8%A1%A8%E6%A0%BC%E7%BB%9F%E8%AE%A1-(%E5%AF%B9%E6%AF%948110%E5%8F%98%E5%8C%96)/?org=UQmaps
|script-title = zh:CMA台站气候标准值(1991-2020)
|publisher =  [[China Meteorological Administration]]
 | language = zh | access-date = 2023-04-11
|title = Experience Template
}}</ref><ref name=CMA>{{cite web
 |url=http://cdc.cma.gov.cn/shuju/index3.jsp?tpcat=SURF&dsid=SURF_CLI_CHN_MUL_MMON_19712000_CES&pageid=3
 |script-title=zh:中国气象局 国家气象信息中心
 | language = zh-hans
 |access-date=2009-03-17
 |publisher=[[China Meteorological Administration]]
 |date=June 2011
 |url-status=dead
 |archive-url=https://web.archive.org/web/20090716061113/http://cdc.cma.gov.cn/shuju/index3.jsp?tpcat=SURF&dsid=SURF_CLI_CHN_MUL_MMON_19712000_CES&pageid=3
 |archive-date=2009-07-16
}}</ref> all-time extreme temperature<ref name = Mherrera>
{{cite web |url=http://www.mherrera.org/temp.htm |title=Extreme Temperatures Around the World|access-date= February 21, 2013|archive-url= https://web.archive.org/web/20140804202145/http://www.mherrera.org/temp.htm|archive-date= August 4, 2014|url-status= live |df=mdy-all}}
</ref>
|date=August 2013}}
{{Weather box
|width = auto
|location = Xi'an (Jinghe Station), elevation {{convert|410|m|ft|abbr=on}}, (2015–2024 normals)

|metric first = Y
|single line  = Y
|collapsed    = Y

|Jan high C = 6.3
|Feb high C = 10.4
|Mar high C = 17.7
|Apr high C = 23.1
|May high C = 27.8
|Jun high C = 32.2
|Jul high C = 33.3
|Aug high C = 32.4
|Sep high C = 27.0
|Oct high C = 19.3
|Nov high C = 13.4
|Dec high C = 7.5
|Jan mean C = 1.6
|Feb mean C = 5.0
|Mar mean C = 12.1
|Apr mean C = 17.1
|May mean C = 21.6
|Jun mean C = 26.3
|Jul mean C = 27.9
|Aug mean C = 27.2
|Sep mean C = 22.1
|Oct mean C = 14.7
|Nov mean C = 8.8
|Dec mean C = 2.8
|year mean C = 	
|Jan low C = -2.0
|Feb low C = 0.9
|Mar low C = 7.6
|Apr low C = 12.1
|May low C = 16.5
|Jun low C = 21.2
|Jul low C = 23.6
|Aug low C = 23.3
|Sep low C = 18.4
|Oct low C = 11.4
|Nov low C = 5.4
|Dec low C = -0.8
|precipitation colour = green	
|Jan precipitation mm = 8.8
|Feb precipitation mm = 13.3
|Mar precipitation mm = 28.4
|Apr precipitation mm = 49.6
|May precipitation mm = 68.0
|Jun precipitation mm = 85.6
|Jul precipitation mm = 103.8
|Aug precipitation mm = 96.7
|Sep precipitation mm = 117.2
|Oct precipitation mm = 66.6
|Nov precipitation mm = 27.9
|Dec precipitation mm = 6.5
|unit precipitation days = 0.1 mm	
|Jan precipitation days = 4.0
|Feb precipitation days = 4.7
|Mar precipitation days = 7.2
|Apr precipitation days = 7.8
|May precipitation days = 9.8
|Jun precipitation days = 9.1
|Jul precipitation days = 10.8
|Aug precipitation days = 10.4
|Sep precipitation days = 12.3
|Oct precipitation days = 11.0
|Nov precipitation days = 6.1
|Dec precipitation days = 3.5
|year precipitation days = 	
|Jan humidity = 67
|Feb humidity = 67
|Mar humidity = 65
|Apr humidity = 66
|May humidity = 66
|Jun humidity = 63
|Jul humidity = 70
|Aug humidity = 76
|Sep humidity = 80
|Oct humidity = 80
|Nov humidity = 77
|Dec humidity = 69
|Jan sun = 120.2
|Feb sun = 121.4
|Mar sun = 160.2
|Apr sun = 185.1
|May sun = 200.1
|Jun sun = 201.2
|Jul sun = 209.3
|Aug sun = 176.1
|Sep sun = 135.2
|Oct sun = 119.8
|Nov sun = 120.6
|Dec sun = 121.7
|year sun = 	
| Jan percentsun = 38
| Feb percentsun = 39
| Mar percentsun = 43
| Apr percentsun = 47
| May percentsun = 46
| Jun percentsun = 47
| Jul percentsun = 48
| Aug percentsun = 43
| Sep percentsun = 37
| Oct percentsun = 35
| Nov percentsun = 39
| Dec percentsun = 40
| year percentsun =	
|Jan snow days = 4.7
|Feb snow days = 3.7
|Mar snow days = 1.3
|Apr snow days = 0.1
|May snow days = 0.1
|Jun snow days = 0
|Jul snow days = 0
|Aug snow days = 0
|Sep snow days = 0
|Oct snow days = 0
|Nov snow days = 1.3
|Dec snow days = 2.8
|year snow days = 	
|source 1 = China Meteorological Administration<ref name="cma graphical">{{cite web |url=http://data.cma.cn/data/weatherBk.html |script-title=zh:中国气象数据网 – WeatherBk Data |publisher=[[China Meteorological Administration]] |language=zh-hans |access-date=3 July 2023 |archive-date=September 5, 2018 |archive-url=https://web.archive.org/web/20180905194950/http://data.cma.cn/data/weatherBk.html |url-status=live }}</ref><ref>{{cite web
|url=https://experience.arcgis.com/template/e724038fda394e9d9b7921f10fd1aa55/page/%E7%BA%AF%E8%A1%A8%E6%A0%BC%E7%BB%9F%E8%AE%A1-(%E5%AF%B9%E6%AF%948110%E5%8F%98%E5%8C%96)/?org=UQmaps
|script-title = zh:CMA台站气候标准值(1991-2020)
|publisher =  [[China Meteorological Administration]]
 | language = zh | access-date = 2023-04-11
|title = Experience Template
}}</ref><ref name=CMA>{{cite web
 |url=http://cdc.cma.gov.cn/shuju/index3.jsp?tpcat=SURF&dsid=SURF_CLI_CHN_MUL_MMON_19712000_CES&pageid=3
 |script-title=zh:中国气象局 国家气象信息中心
 | language = zh-hans
 |access-date=2009-03-17
 |publisher=[[China Meteorological Administration]]
 |date=June 2011
 |url-status=dead
 |archive-url=https://web.archive.org/web/20090716061113/http://cdc.cma.gov.cn/shuju/index3.jsp?tpcat=SURF&dsid=SURF_CLI_CHN_MUL_MMON_19712000_CES&pageid=3
 |archive-date=2009-07-16
}}</ref> all-time extreme temperature<ref name = Mherrera>
{{cite web |url=http://www.mherrera.org/temp.htm |title=Extreme Temperatures Around the World|access-date= February 21, 2013|archive-url= https://web.archive.org/web/20140804202145/http://www.mherrera.org/temp.htm|archive-date= August 4, 2014|url-status= live |df=mdy-all}}
</ref>
|date=August 2013}}

===National Time Service Center===
The [[National Time Service Center|Shaanxi Astronomical Observatory]] was established in 1966. In 1975, according to the Geodetic Origin Report of the People's Republic of China, 'in order to avoid bias in the mensuration as much as possible, the Geodetic Origin would be in central mainland China.' Lintong ({{lang|zh-hans|临潼}}), a town near Xi'an was chosen. Since 1986, Chinese Standard Time (CST) was set from NTSC. The National Time Service Center (NTSC), the Chinese Academy of Sciences is an institute which is mainly engaged in the service and research on time and frequency. NTSC takes charge of generating and maintaining the national standard time scale, disseminating the time and frequency signals. The autonomous standard time scales of universal time and atomic time and the dissemination techniques with LF radio and HF radio were established successively during the 1970s and 1980s, which meet all the requirements for different applications on the whole, such as the scientific researches, national economy, etc.<ref>[http://www.time.ac.cn/jianjie/1.htm NTSC] {{webarchive |url=https://web.archive.org/web/20160304001755/http://www.time.ac.cn/jianjie/1.htm |date=March 4, 2016 }} 国家授时中心简介</ref>