the east disrupts the winds resulting to a dry period. From May to September, the southwest monsoon (habagat). The hottest month is May with an average temperature of while the coldest is February with an average temperature of . Administrative divisions Bulacan is subdivided into 21 municipalities and 4 cities. As the population is concentrated in the southern half of the province, so are the legislative districts. Demographics The population of Bulacan in the 2020 census was 3,708,890 people, making it the second most populous province in the country, only behind from Cavite, which is also located in Luzon. It had a density of , the country's 4th highest for a province. On May 1, 2010, the province had 2,924,433 inhabitants with an annual population growth rate of 2.73 from the year 2000 to 2010, There were 588,693 households in the province with an average size of 4.8 persons. Bulacan had a median age of 23 years in 2007. Languages and ethnicities As it is part of the Tagalog cultural sphere (Katagalugan), Tagalog is the predominant language of Bulacan. The Tagalog dialect spoken in Bulacan resembles a poetic form of speech. Some inhabitants also speak Kapampangan, especially in areas close to the border of Pampanga. Three municipalities (San Miguel, Remedios Trinidad, and Norzagaray) and one city (San Jose del Monte) are the homelands of the Alta Kabulowan, the first inhabitants of Bulacan, whose language is also called Alta Kabulowan. Their language is currently endangered due to an influx of Tagalog speakers. San Jose del Monte City, Santa Maria, Malolos, Marilao, San Miguel and Norzagaray bear the highest number of English speakers in the province. Religion Roman Catholic (89.44%) is the predominant religion in the province. Malolos City is the seat of the Roman Catholic Diocese of Malolos, with its mother church, the Minor Basilica and Cathedral of the Immaculate Conception. On March 21, 2021, Sta. Maria Church was also granted the status of Minor Basilica by Pope Francis. It became Bulacan's second Minor Basilica and the 18th in the Philippines. Other Christian groups include the Iglesia ni Cristo (3.29%), Evangelicals (1.53%), Jehovah's Witnesses (0.37%), Bible Baptist Church (0.30%), Muslims (0.21%), Seventh-day Adventist (0.21%), Aglipayans (0.17%) and other small number of Christians and non-Christian groups are also present. Economy Industries The province of Bulacan is steadily becoming industrialized due to its proximity to Metro Manila. Many corporations put up industrial plants