Popian (French pronunciation: [pɔpjɑ̃]) is a commune in the Hérault department in the Occitanie region in southern France.

The neighboring communes are Gignac, Saint-Bauzille-de-la-Sylve, Le Pouget and Pouzols.

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 period from 1971 to 2000, the average annual temperature was 14.4 °C (58 °F) with an annual atmospheric temperature of 16.5 °C (62 °F). The average annual total rainfall during this period was 774 mm, with 6.4 days of precipitation in January and 2.7 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 Saint-André-de-Sangonis, 4 km away as the crow flies, is 15.5 °C (60 °F), and the average annual total rainfall is 652.4 mm.

For the future, climate parameters for the municipality 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 2008.

In 2021, the commune had a population of 355, reflecting an increase of +2.31 since 2015 (Hérault: +7.29%, France excluding Mayotte: +1.84%).

Historical population

Year Pop. ±% p.a. 1793 183 —     1800 153 −2.53% 1806 198 +4.39% 1821 199 +0.03% 1831 174 −1.33% 1836 180 +0.68% 1841 168 −1.37% 1846 154 −1.73% 1851 170 +2.00% 1856 153 −2.09% 1861 128 −3.51% 1866 149 +3.08% 1872 159 +1.09% 1876 157 −0.32% 1881 123 −4.76% 1886 118 −0.83% 1891 141 +3.63% 1896 140 −0.14% 1901 171 +4.08%	Year Pop. ±% p.a. 1906 182 +1.25% 1911 156 −3.04% 1921 187 +1.83% 1926 225 +3.77% 1931 251 +2.21% 1936 239 −0.98% 1946 169 −3.41% 1954 217 +3.17% 1962 233 +0.89% 1968 214 −1.41% 1975 198 −1.10% 1982 168 −2.32% 1990 195 +1.88% 1999 248 +2.71% 2006 322 +3.80% 2008 343 +3.21% 2013 346 +0.17% 2018 351 +0.29% 2021 355 +0.38%
Source: Ldh/EHESS/Cassini until 1999, and INSEE since 2006.

• Communes of the Hérault department