Geography of Louisville, Kentucky
Louisville is located at 38°13′31″N 85°44′30″W / 38.225371°N 85.741613°W.
Topography and geomorphology
Although the soils and underlying rocks officially put Louisville in the outer
The flood plain is much longer north to south than it is east to west. For example, within several miles of downtown, the
Areas along and west of the south fork of
Areas east of I-65 were generally not in the flood plain and thus are mostly gentle rolling hills composed of soft
Political geography and population
The
Louisville's Metro Area was expanded more than any other in the country during a March 2003 overhaul of U.S. Metropolitan Area statistics by the federal government. In the 2000 census, even very fast growing counties such as Spencer County weren't included. The Metro Area's ranking rose from 49th to 42nd, and the added Combined Statistical Area measured the area as the nation's 31st-largest. The total Metro area population also increased dramatically from just over 1 million to nearly 1.4 for the CSA.
Seventeen percent of the state's population lives in Jefferson County and 25% live in counties in the Louisville CSA, and also Jefferson County has two-and-a-half times more people than Kentucky's second-most populous county, Fayette County. Fourteen of the 18 buildings in Kentucky over 300 feet are located in Downtown Louisville.
Climate
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Climate chart (explanation) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Louisville has a
The wettest seasons are spring and summer, although rainfall is fairly constant year round. During the winter, particularly in January and February, several days of snow can be expected. January is the coldest month, with a mean temperature of 34.9 °F (1.6 °C). July is the average hottest month with a mean of 79.3 °F (26.3 °C).[6] The highest recorded temperature was 107 °F (42 °C), which last occurred on July 14, 1936, and the lowest recorded temperature was −22 °F (−30 °C) on January 19, 1994.[7] The record high daily minimum was 84 °F (29 °C) on August 19, 1936, while the record low daily maximum was −2 °F (−19 °C) on January 12, 1918; the only other sub-0 °F (−18 °C) daily maximum occurred on January 5, 1884. In 2012, Louisville had the fourth-hottest summer on record, with the temperature rising up to 106 °F (41 °C) in July and the June all-time monthly record-high temperature being broken on two consecutive days.[5] As the city exemplifies the urban heat island effect, temperatures in commercial areas and in the industrialized areas along interstates are often higher than in the suburbs, often as much as 5 °F (2.8 °C).
A 2012 study by the Urban Climate Lab at Georgia Tech shows that Louisville has the highest index of the heat island effect in America. According to Brian Stone of the Urban Climate Lab and author of The City and the Coming Climate, "The average increase in the temperature difference between urban and rural environments in the Louisville area has been 1.67 degrees Fahrenheit every decade between 1961 and 2010. That's nearly double the rate of the next city on the list, Phoenix, which saw an average change of .96 degrees in the same period." Stone said that part of Louisville's problem stems from the unfortunate meteorological conditions of the Ohio River Valley, which is prone to stagnant air conditions but also that the lack of tree cover in the urban core contributes as well. Stone states that "The tree canopy downtown is one of the sparsest of any city I have seen in the country." The tree cover in Louisville's larger metro area is around 30 percent, according to Stone's research, with the urban core at just 10 percent. That compares to about 45 percent in the city of Atlanta.[8]
Louisville's lowest solar noon is 28.4 degrees with the shortest daylength being 9 hours and 30 seconds, both occurring from December 17–26. The city's highest solar noon is 75.2 degrees with the longest daylength being 14 hours and 39 seconds, both occurring from June 17–25. The city's March and September equinox occurs at 50.5 degrees.[10]
Climate data for Louisville International Airport, Kentucky (1991–2020 normals,[e] extremes 1872–present[f]) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Record high °F (°C) | 77 (25) |
82 (28) |
88 (31) |
91 (33) |
98 (37) |
105 (41) |
107 (42) |
105 (41) |
104 (40) |
97 (36) |
85 (29) |
76 (24) |
107 (42) |
Mean maximum °F (°C) | 65.2 (18.4) |
70.4 (21.3) |
77.8 (25.4) |
84.1 (28.9) |
89.0 (31.7) |
93.6 (34.2) |
95.7 (35.4) |
95.6 (35.3) |
92.9 (33.8) |
85.4 (29.7) |
75.1 (23.9) |
67.0 (19.4) |
97.3 (36.3) |
Mean daily maximum °F (°C) | 43.6 (6.4) |
48.3 (9.1) |
58.1 (14.5) |
69.6 (20.9) |
77.8 (25.4) |
85.7 (29.8) |
89.0 (31.7) |
88.4 (31.3) |
82.2 (27.9) |
70.5 (21.4) |
57.6 (14.2) |
47.2 (8.4) |
68.2 (20.1) |
Daily mean °F (°C) | 35.7 (2.1) |
39.5 (4.2) |
48.4 (9.1) |
59.0 (15.0) |
68.3 (20.2) |
76.4 (24.7) |
79.9 (26.6) |
78.9 (26.1) |
72.0 (22.2) |
60.3 (15.7) |
48.5 (9.2) |
39.6 (4.2) |
58.9 (14.9) |
Mean daily minimum °F (°C) | 27.8 (−2.3) |
30.7 (−0.7) |
38.6 (3.7) |
48.5 (9.2) |
58.7 (14.8) |
67.2 (19.6) |
70.8 (21.6) |
69.5 (20.8) |
61.9 (16.6) |
50.1 (10.1) |
39.4 (4.1) |
32.1 (0.1) |
49.6 (9.8) |
Mean minimum °F (°C) | 6.0 (−14.4) |
11.4 (−11.4) |
20.3 (−6.5) |
31.7 (−0.2) |
41.9 (5.5) |
53.6 (12.0) |
60.5 (15.8) |
58.7 (14.8) |
46.9 (8.3) |
33.7 (0.9) |
23.1 (−4.9) |
13.0 (−10.6) |
3.3 (−15.9) |
Record low °F (°C) | −22 (−30) |
−19 (−28) |
−1 (−18) |
21 (−6) |
31 (−1) |
42 (6) |
49 (9) |
45 (7) |
33 (1) |
23 (−5) |
−1 (−18) |
−15 (−26) |
−22 (−30) |
Average precipitation inches (mm) | 3.39 (86) |
3.41 (87) |
4.60 (117) |
4.80 (122) |
5.18 (132) |
4.27 (108) |
4.05 (103) |
3.71 (94) |
3.66 (93) |
3.72 (94) |
3.42 (87) |
4.13 (105) |
48.34 (1,228) |
Average snowfall inches (cm) | 4.5 (11) |
4.1 (10) |
2.1 (5.3) |
0.1 (0.25) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.1 (0.25) |
0.3 (0.76) |
2.2 (5.6) |
13.4 (34) |
Average precipitation days (≥ 0.01 in) | 11.2 | 10.4 | 12.1 | 11.9 | 12.6 | 10.5 | 10.2 | 8.2 | 7.9 | 7.9 | 9.8 | 11.8 | 124.5 |
Average snowy days (≥ 0.1 in) | 3.7 | 3.7 | 1.7 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.6 | 2.5 | 12.3 |
Average relative humidity (%)
|
68.6 | 68.1 | 64.0 | 61.5 | 67.2 | 68.9 | 70.9 | 71.7 | 72.9 | 69.9 | 69.4 | 70.2 | 68.6 |
Mean monthly sunshine hours | 140.5 | 148.9 | 188.6 | 221.1 | 263.4 | 288.9 | 293.6 | 272.6 | 234.3 | 208.5 | 135.7 | 118.3 | 2,514.4 |
Percent possible sunshine | 46 | 49 | 51 | 56 | 60 | 65 | 65 | 65 | 63 | 60 | 45 | 40 | 56 |
Average ultraviolet index | 1.8 | 2.8 | 4.6 | 6.5 | 8.0 | 8.9 | 9.1 | 8.2 | 6.4 | 4.0 | 2.3 | 1.6 | 5.3 |
Source 1: NOAA (relative humidity and sun 1961–1990)[11][5][12] | |||||||||||||
Source 2: UV Index Today (1995 to 2022)[13] |
See also
Notes
- ^ The number of 90 °F+ days has historically ranged from 3 in 1974 to 85 in 2010.[5]
- ^ The coolest year on record was 53.6 °F (12.0 °C) in 1917, while the warmest 60.8 °F (16.0 °C) in 2012. Monthly mean temperatures have ranged from 18.6 °F (−7.4 °C) in January 1977 to 85.0 °F (29.4 °C) in August 2007, although the highest average monthly minimum temperature was 74.5 °F (23.6 °C) in July 2011.[5]
- ^ Historically, winter snowfall has ranged from 0.9 in (2.3 cm) in 1988–89 to 50.2 in (128 cm) in 1917–18.
- ^ Annual precipitation has ranged from 23.88 in (607 mm) in 1930 to 68.02 in (1,728 mm) in 2011.
- ^ Mean monthly maxima and minima (i.e. the expected highest and lowest temperature readings at any point during the year or given month) calculated based on data at said location from 1991 to 2020.
- ^ Official records for Louisville were kept at the Weather Bureau Office from August 1872 to June 1945, Bowman Field from July 1945 to November 1947, Louisville Int'l from December 1947 to October 1995, the Weather Forecast Office (38°06′54″N 85°38′42″W / 38.1150°N 85.6450°W) from November 1995 to December 2005, and again at Louisville Int'l since January 2006. For more information, see Threadex
References
- ^ "U.S. Gazetteer file for Kentucky places (Louisville city)". United States Census Bureau. 2015. Archived from the original on February 8, 2017. Retrieved August 26, 2016.
- ^ "U.S. Gazetteer file for Kentucky counties (Jefferson County)". United States Census Bureau. 2015. Archived from the original on February 8, 2017. Retrieved August 26, 2016.
- ^ "Table 1. Annual Estimates of the Population of Metropolitan and Micropolitan Statistical Areas: April 1, 2010 to July 1, 2013" (CSV). 2013 Population Estimates. United States Census Bureau, Population Division. March 2014. Retrieved June 15, 2014.[permanent dead link]
- ^ "USDA Plant Hardiness Zone Interactive Map". Planthardiness.ars.usda.gov. Archived from the original on February 9, 2014. Retrieved March 31, 2014.
- ^ a b c d e f "NowData – NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved June 2, 2021.
- ^ Climate information from NOAA Archived September 4, 2013, at the Wayback Machine
- ^ Maximum and minimum temperatures from Yahoo! Weather
- ^ Goodyear, Sarah (May 8, 2013). "There Are Few Trees in Louisville, America's Fastest Warming City". Next City. Archived from the original on December 6, 2013. Retrieved March 31, 2014.
- ^ "Clean Air in your city". Environmental Defense. Archived from the original on August 13, 2007. Retrieved July 24, 2007.
- ^ "Sunrise and sunset in Louisville – Kentucky – U.S.A". Timeanddate.com. Archived from the original on June 12, 2011. Retrieved January 27, 2011.
- ^ "Station Name: KY Louisville Intl. AP". U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991–2020). National Oceanic and Atmospheric Administration. Retrieved June 2, 2021.
- ^ "WMO Climate Normals for Louisville/Standiford Field KY 1961–1990". National Oceanic and Atmospheric Administration. Retrieved March 11, 2014.
- ^ "Historical UV Index Data - Louisdville, KY". UV Index Today. Retrieved April 21, 2023.
Further reading
- Conkin, Barbara (2003). Why Are The Highlands High?: The Geology beneath the Landscapes of Jefferson County. ISBN 0-9674662-7-X.
External links
- LOJIC Online – Interactive map of Louisville Metro
- Historic Maps of Louisville/Jefferson County, Kentucky – University of Louisville Libraries