Editing Alton, Illinois (section)

==Geography==
Alton is located on the [[Mississippi River]] above the mouth of the [[Missouri River]]. Most of Alton is located on bluffs overlooking the river valley. The [[Meeting of the Great Rivers Scenic Route|Meeting of the Great Rivers National Scenic Byway]] runs along the Alton riverfront. A monument and observatory tower, [[Confluence Tower]], located next to the confluence of the Missouri and Mississippi Rivers in neighboring [[Hartford, Illinois|Hartford, IL]], has been constructed to provide an overview of the Great Rivers area. This point also marks the beginning of the famous [[Lewis and Clark Expedition]]. Also on the river at Alton is [[Melvin Price Locks and Dam|Lock and Dam 26]], the newest and busiest lock and dam complex on the main channel of the Mississippi River. Adjacent to it on the Illinois side is the {{ill|National Great Rivers Museum |qid=Q113406977}}, which features tours of the dam itself several times per day. On the Missouri side is the [[List of nature centers in Missouri|Audubon Center at Riverlands]], which is one of the best places in the world to view birds, as it lies near where the [[Mississippi Flyway]] merges the flight paths of the Mississippi, Illinois, and Missouri rivers. Also adjacent to the Audubon Center is the [[Jones-Confluence Point State Park]], where one can stand at the confluence of the Missouri and Mississippi Rivers.

According to the 2010 census, Alton has a total area of {{convert|16.736|sqmi|sqkm|2}}, of which {{convert|15.47|sqmi|sqkm|2}} (or 92.44%) is land and {{convert|1.266|sqmi|sqkm|2}} (or 7.56%) is water.<ref name="census-g001">{{Cite web |title=G001 – Geographic Identifiers – 2010 Census Summary File 1 |url=http://factfinder.census.gov/bkmk/table/1.0/en/DEC/10_SF1/G001/1600000US1701114 |url-status=dead |archive-url=https://archive.today/20200213042308/http://factfinder.census.gov/bkmk/table/1.0/en/DEC/10_SF1/G001/1600000US1701114 |archive-date=February 13, 2020 |access-date=2015-12-25 |publisher=[[United States Census Bureau]]}}</ref>

The National Great Rivers Museum is located at the new Lock and Dam No. 26, or [[Melvin Price Locks and Dam]]. The lock and dam are open for tours. The lock is a favorite spot to watch [[bald eagle]]s, which feed on fish coming up in waters below the dam. A large bird [[sanctuary]] is located in an area of floodplain and wetlands on the west side of the river.

[[File:Great River Road Alton-Grafton 1.jpg|thumb|right|The Great River Road in Illinois north of Alton, looking south]]

The River Road goes right next to the river north to [[Grafton, Illinois|Grafton]]. Above that, it is often routed inland of the floodplain. It provides views of the dramatic contrast between the high cliffs of the Illinois side to the broad, flat, green agricultural countryside of [[Portage des Sioux, Missouri]]. The [[Great River Road]] is a popular [[bicycle touring]] route. Hidden in a notch of the cliff is the tiny village of [[Elsah, Illinois|Elsah]], once a down-and-dirty, liquor-soaked tugboaters' retreat, now with renovated properties and antique shops in historic houses.{{citation needed|date=January 2023}}

===Climate===
{{Weather box
|location = Alton, Illinois (1991–2020 normals, extremes 1943–present)
|single line = Y
| Jan record high F = 77
| Feb record high F = 76
| Mar record high F = 89
| Apr record high F = 102
| May record high F = 98
| Jun record high F = 107
| Jul record high F = 116
| Aug record high F = 106
| Sep record high F = 103
| Oct record high F = 98
| Nov record high F = 88
| Dec record high F = 74
| year record high F = 116
| Jan high F = 39.5
| Feb high F = 43.7
| Mar high F = 53.5
| Apr high F = 66.1
| May high F = 75.0
| Jun high F = 83.7
| Jul high F = 87.3
| Aug high F = 86.0
| Sep high F = 80.1
| Oct high F = 67.9
| Nov high F = 54.3
| Dec high F = 43.5
| year high F = 65.0
| Jan mean F = 30.3
| Feb mean F = 34.5
| Mar mean F = 44.1
| Apr mean F = 55.6
| May mean F = 65.6
| Jun mean F = 74.6
| Jul mean F = 78.3
| Aug mean F = 76.6
| Sep mean F = 70.0
| Oct mean F = 57.9
| Nov mean F = 45.4
| Dec mean F = 35.3
| year mean F = 55.7
| Jan low F = 21.7
| Feb low F = 25.2
| Mar low F = 34.7
| Apr low F = 45.2
| May low F = 56.1
| Jun low F = 65.6
| Jul low F = 69.3
| Aug low F = 67.3
| Sep low F = 59.8
| Oct low F = 48.0
| Nov low F = 36.5
| Dec low F = 27.1
| year low F = 46.4
| Jan record low F = −16
| Feb record low F = −15
| Mar record low F = −1
| Apr record low F = 20
| May record low F = 32
| Jun record low F = 44
| Jul record low F = 50
| Aug record low F = 46
| Sep record low F = 37
| Oct record low F = 25
| Nov record low F = 4
| Dec record low F = −16
| year record low F = -16
| precipitation colour = green
| Jan precipitation inch = 2.53
| Feb precipitation inch = 2.52
| Mar precipitation inch = 3.46
| Apr precipitation inch = 4.92
| May precipitation inch = 5.46
| Jun precipitation inch = 3.40
| Jul precipitation inch = 3.95
| Aug precipitation inch = 3.30
| Sep precipitation inch = 3.38
| Oct precipitation inch = 2.93
| Nov precipitation inch = 3.43
| Dec precipitation inch = 2.59
| year precipitation inch = 41.87
| unit precipitation days = 0.01 in
| Jan precipitation days = 7.2
| Feb precipitation days = 7.8
| Mar precipitation days = 9.9
| Apr precipitation days = 10.3
| May precipitation days = 11.3
| Jun precipitation days = 8.2
| Jul precipitation days = 7.3
| Aug precipitation days = 7.0
| Sep precipitation days = 6.8
| Oct precipitation days = 7.6
| Nov precipitation days = 8.2
| Dec precipitation days = 7.7
| year precipitation days = 99.3
|source 1 = [[NOAA]]<ref name="NOAA">{{Cite web |title=NowData – NOAA Online Weather Data |url=https://w2.weather.gov/climate/xmacis.php?wfo=lsx |access-date=July 24, 2021 |publisher=National Oceanic and Atmospheric Administration}}</ref><ref name="NCEI">{{Cite web |title=Station: Alton–Melvin Prince L&D, IL |url=https://www.ncei.noaa.gov/access/services/data/v1?dataset=normals-monthly-1991-2020&startDate=0001-01-01&endDate=9996-12-31&stations=USC00110137&format=pdf |access-date=July 24, 2021 |website=U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991–2020) |publisher=National Oceanic and Atmospheric Administration}}</ref>
}}