Geography and demographics
[edit]
Historical populationYearPop.±%14903,800—    17844,366+14.9%18718,260+89.2%190020,677+150.3%191038,487+86.1%191948,847+26.9%192552,649+7.8%193358,357+10.8%193970,632+21.0%195080,309+13.7%196484,307+5.0%197088,130+4.5%1981104,946+19.1%1991100,967−3.8%2001101,157+0.2%2011105,739+4.5%2022110,369+4.4%Population size may be affected by changes in administrative divisions.
source:
Topography[edit]
The medieval bridge across the Saale in Burgau district
Jena is situated in a hilly landscape in eastern Thuringia at the Saale river, between the Harz mountains 85 km (53 mi) in the north, the Thuringian Forest/Thuringian Highland 50 km (31 mi) in the southwest and the Ore Mountains, 75 km (47 mi) in the southeast. The municipal terrain is hilly with rugged slopes at the valley's edges. The city centre is situated at 160 m of elevation, whereas the mountains on both sides of Saale valley rise up to 400 m. On the eastern side those are (from north to south): the Gleisberg near Kunitz, the Jenzig near Wogau, the Hausberg near Wenigenjena, the Kernberge near Wöllnitz, the Johannisberg near Lobeda and the Einsiedlerberg near Drackendorf. On the western side, there are the Jägersberg near Zwätzen, the Windknollen north of the city centre, the Tatzend west of the city centre, the Lichtenhainer Höhe near Lichtenhain, the Holzberg near Winzerla, the Jagdberg near Göschwitz and the Spitzenberg near Maua. The mountains belong to the geological formation of Ilm Saale Plate (Muschelkalk) and are relatively flat on their peaks but steep to the valleys in between. Due to its jagged surface, the municipal territory isn't very suitable for agriculture all the more since the most flat areas along the valley were built on during the 20th century. At the mountains is some forest of different leaf trees and pines.
Ecology[edit]
32 species of native orchids can be found in the Jena area. One of the best places to see them is Leutratal, to the south of the town. Bee orchid (Ophrys apifera) even grows at a few locations within the town. On the Hausberg close to Ziegenhain a few specimens of the rare true service tree (Cormus domestica) can be found. Firefly can be seen in the meadows in Paradiespark as well as a variety of native wildflowers. Wildlife on the surrounding mountains includes raven, sand lizard and wood ants. Heron, beaver and muskrat have been seen on the Saale, within the town. Pine martens sometimes come into the town at night, from the mountains, to raid bins. It is documented that the European wildcat occurs near Jena.
Climate[edit]
Jena has an oceanic climate (Köppen: Cfb; Trewartha: Dobk). Summers are warm and sometimes humid; winters are relatively cold. The city's topography creates a microclimate caused through the basin position with sometimes inversion in winter (quite cold nights under −20 °C (−4 °F)) and heat and inadequate air circulation in summer. Annual precipitation is 585 millimeters (23.0 in) with moderate rainfall throughout the year. Light snowfall mainly occurs from December through February, but snow cover does not usually remain for long. During the Middle Ages, Jena was famous for growing wine on its slopes. Nowadays, the next commercial wine-growing areas are situated 20 km (12 mi) down Saale river. Due to its distance to coastal areas and position in the Saale valley, wind speeds tend to be very low; predominant direction is SW.
The Jena weather station has recorded the following extreme values:
Its highest temperature was 39.1 °C (102.4 °F) on 20 July 2022.
Its lowest temperature was −30.6 °C (−23.1 °F) on 22 January 1850 and 2 February 1830.
Its greatest annual precipitation was 849.7 mm (33.45 in) in 1882.
Its least annual precipitation was 379.4 mm (14.94 in) in 1911.
The longest annual sunshine was 1928.8 hours in 2003.
The shortest annual sunshine was 1108.6 hours in 1960.
Climate data for Jena, 1991–2020 normals, extremes 1821–present
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Record high °C (°F)
17.0(62.6)
23.1(73.6)
25.9(78.6)
32.5(90.5)
36.1(97.0)
38.8(101.8)
39.1(102.4)
38.7(101.7)
36.5(97.7)
29.0(84.2)
23.1(73.6)
17.7(63.9)
39.1(102.4)
Mean maximum °C (°F)
12.5(54.5)
14.5(58.1)
19.7(67.5)
25.2(77.4)
29.5(85.1)
32.6(90.7)
34.0(93.2)
33.8(92.8)
28.5(83.3)
23.2(73.8)
16.4(61.5)
13.0(55.4)
35.8(96.4)
Mean daily maximum °C (°F)
4.6(40.3)
6.2(43.2)
10.6(51.1)
16.2(61.2)
20.4(68.7)
23.7(74.7)
26.0(78.8)
25.7(78.3)
20.7(69.3)
15.0(59.0)
8.9(48.0)
5.3(41.5)
15.3(59.5)
Daily mean °C (°F)
1.7(35.1)
2.5(36.5)
5.7(42.3)
10.1(50.2)
14.3(57.7)
17.7(63.9)
19.7(67.5)
19.1(66.4)
14.6(58.3)
10.1(50.2)
5.6(42.1)
2.6(36.7)
10.3(50.5)
Mean daily minimum °C (°F)
−1.2(29.8)
−1.0(30.2)
1.5(34.7)
4.5(40.1)
8.4(47.1)
12.0(53.6)
14.0(57.2)
13.6(56.5)
9.9(49.8)
6.1(43.0)
2.6(36.7)
−0.1(31.8)
5.9(42.6)
Mean minimum °C (°F)
−10.9(12.4)
−9.2(15.4)
−5.0(23.0)
−1.6(29.1)
2.2(36.0)
6.6(43.9)
9.1(48.4)
8.0(46.4)
4.2(39.6)
−0.8(30.6)
−3.9(25.0)
−8.7(16.3)
−13.3(8.1)
Record low °C (°F)
−30.6(−23.1)
−30.6(−23.1)
−24.0(−11.2)
−12.4(9.7)
−5.1(22.8)
0.6(33.1)
3.7(38.7)
3.4(38.1)
−4.4(24.1)
−10.9(12.4)
−24.6(−12.3)
−28.8(−19.8)
−30.6(−23.1)
Average precipitation mm (inches)
35.3(1.39)
30.4(1.20)
41.9(1.65)
36.9(1.45)
61.2(2.41)
54.8(2.16)
85.1(3.35)
67.6(2.66)
50.8(2.00)
41.6(1.64)
47.3(1.86)
42.8(1.69)
595.6(23.45)
Average extreme snow depth cm (inches)
7.2(2.8)
5.4(2.1)
3.3(1.3)
0.3(0.1)
0(0)
0(0)
0(0)
0(0)
0(0)
0.2(0.1)
1.3(0.5)
5.6(2.2)
10.6(4.2)
Average precipitation days (≥ 0.1 mm)
16.9
14.7
15.9
12.5
14.1
13.9
14.7
13.6
12.2
14.1
15.5
17.4
175.5
Average relative humidity (%)
78.7
75.2
71.0
66.0
67.1
67.2
66.4
68.4
74.9
79.3
81.7
80.6
73.0
Mean monthly sunshine hours
59.1
80.7
107.7
160.4
191.4
182.6
197.4
213.2
136.3
104.9
53.6
44.8
1,532.1
Source: Deutscher Wetterdienst / SKlima.de
Administrative division[edit]
Jena abuts the district of Saale-Holzland with the municipalities of Lehesten, Neuengönna, and Golmsdorf in the north, Jenalöbnitz, Großlöbichau, and Schlöben in the east and Laasdorf, Zöllnitz, Sulza, Rothenstein, Milda, and Bucha in the south and the district of Weimarer Land with the municipalities of Döbritschen, Großschwabhausen, and Saaleplatte in the west.
The city is divided into 30 districts. The inner-city districts are Zentrum, Nord, West, Süd, Wenigenjena (east of Saale, incorporated in 1909), and Kernberge, other big districts are Lobeda (incorporated in 1946) and Winzerla (incorporated in 1922) in the south with large housing complexes.
Outlying districts are more rural in character:
Ammerbach (incorporated 1922)
Burgau (1922)
Closewitz (1994)
Cospeda (1994)
Drackendorf (1994)
Göschwitz (1969)
Ilmnitz (1994)
Isserstedt (1994)
Jenaprießnitz/Wogau (1994)
Krippendorf (1994)
Kunitz/Laasan (1994)
Leutra (1994)
Lichtenhain (1913)
Löbstedt (1922)
Lützeroda (1994)
Maua (1994)
Münchenroda/Remderoda (1994)
Vierzehnheiligen (1994)
Wöllnitz (1946)
Ziegenhain (1913)
Zwätzen (1922)
Demographics[edit]
Population development until 2017
Ten largest groups of foreign residents
Nationality
Population (31 December 2017)
Poland
800
Russia
585
India
540
Ukraine
500
Over the centuries, Jena had mostly been a town of 4,000 to 5,000 inhabitants. The population growth began in the 19th century with an amount of 6,000 in 1840 and of 8,000 in 1870. Then, a demographic boom occurred with a population of 20,000 in 1900, 50,000 in 1920, 73,000 in 1940, 81,000 in 1960 and 104,000 in 1980. The peak was reached in 1988 with a population of 108,000. The bad economic situation in eastern Germany after the reunification resulted in a decline in population, which fell to 99,000 in 1998 before rising again to 107,000 in 2012.
The average population growth between 2009 and 2012 was approximately 0.47% p. a, whereas the population in bordering rural regions is shrinking with accelerating tendency. Suburbanization played only a small role in Jena. It occurred after the reunification for a short time in the 1990s, but most of the suburban areas were situated within the administrative city borders.
The birth surplus was 62 in 2012, or +0.6 per 1,000 inhabitants (Thuringian average: -4.5; national average: -2.4). The net migration rate was +4.0 per 1,000 inhabitants in 2012 (Thuringian average: -0.8; national average: +4.6). The most important regions of origin of Jena migrants are rural areas of Thuringia, Saxony-Anhalt and Saxony as well as foreign countries such as Poland, Russia, Ukraine, Hungary, Serbia, Romania, and Bulgaria.
Like many other eastern German cities, Jena has a small foreign-born population: circa 4.0% are non-Germans by citizenship and overall 6.2% are migrants (according to 2011 EU census). Differing from the national average, the biggest groups of migrants in Jena are Russians, Chinese and Ukrainians. During recent years, the economic situation of the city has improved: the unemployment rate declined from 14% in 2005 to 7% in 2013. Due to the official policy of atheism in the former GDR, most of the population is non-religious. 15.9% are members of the Evangelical Church in Central Germany and 6.6% are Catholics (according to 2011 EU census).