Jacou (French pronunciation: [ʒaku] ; Occitan: Jacon) is a commune in the Hérault département in the Occitanie region in southern France. Located on the outskirts of Montpellier, it is situated around 7 km (4.3 mi) north of the Montpellier city centre.

The commune borders Clapiers to the west, Castelnau-le-Lez to the south, Le Crès to the east, and Teyran to the north.

In 2010, the climate of the commune is classified as a frank Mediterranean climate, according to a study based on a dataset covering the 1971-2000 period. In 2020, Météo-France published a typology of climates in mainland France in which the commune is exposed to a Mediterranean climate and is part of the Provence, Languedoc-Roussillon climatic region, characterized by low rainfall in summer, very good sunshine (2,600 h/year), a hot summer 21.5 °C (71 °F), very dry air in summer, dry conditions in all seasons, strong winds (with a frequency of 40 to 50% for winds > 5 m/s), and little fog.

For the 1971-2000 period, the average annual temperature was 14.2 °C (58 °F) with an annual atmospheric temperature of 16.6 °C (62 °F). The average annual total rainfall during this period was 746 mm, with 6 days of precipitation in January and 2.8 days in July. For the subsequent period of 1991 to 2020, the average annual temperature observed at the nearest weather station, located in the commune of Prades-le-Lez, 6 kilometres (4 mi) away as the crow flies, is 14.6 °C (58 °F), and the average annual total rainfall is 869.7 mm.

For the future, climate parameters for the commune projected for 2050, based on different greenhouse gas emission scenarios, can be consulted on a dedicated website published by Météo-France in November 2022.

Changes in the number of inhabitants have been documented through population censuses conducted in the commune since 1793. For communes with fewer than 10,000 inhabitants, a full census of the population is conducted every five years, with the legal populations for the intervening years estimated through interpolation or extrapolation. For this commune, the first complete census under the new system was carried out in 2004.

In 2021, the commune had a population of 6,823, reflecting an increase of +0.99 since 2015 (Hérault: +7.29%, France excluding Mayotte: +1.84%).

Historical population

Year Pop. ±% p.a. 1793 81 —     1800 61 −3.97% 1806 92 +7.09% 1821 85 −0.53% 1831 88 +0.35% 1836 90 +0.45% 1841 117 +5.39% 1846 111 −1.05% 1851 145 +5.49% 1856 139 −0.84% 1861 132 −1.03% 1866 145 +1.90% 1872 153 +0.90% 1876 141 −2.02% 1881 134 −1.01% 1886 120 −2.18% 1891 125 +0.82% 1896 124 −0.16% 1901 160 +5.23% 1906 164 +0.50%	Year Pop. ±% p.a. 1911 152 −1.51% 1921 175 +1.42% 1926 159 −1.90% 1931 179 +2.40% 1936 160 −2.22% 1946 209 +2.71% 1954 241 +1.80% 1962 223 −0.97% 1968 247 +1.72% 1975 1,259 +26.20% 1982 1,774 +5.02% 1990 3,795 +9.97% 1999 4,757 +2.54% 2004 5,044 +1.18% 2006 4,997 −0.47% 2009 4,824 −1.17% 2014 6,584 +6.42% 2019 6,808 +0.67% 2021 6,823 +0.11%
Source: Ldh/EHESS/Cassini until 1999, and INSEE since 2006.

• Communes of the Hérault department