Bihar Weather, AQI and Fuel Prices

Why Check Bihar Weather & Data?

Bihar is home to an estimated 13.1 to 13.4 crore people as of 2025, third most populous state in India by the last full Census in 2011, though several 2025-26 population projections now place it ahead of Maharashtra in second place, a shift the Census itself has not yet confirmed. Its GSDP reached roughly ₹9.92 lakh crore in 2024-25, growing 13.1 percent in nominal terms, yet per capita income stood at just ₹69,321 that same year, the lowest of any major Indian state and barely a third of the national average. Agriculture carries much of that weight. Muzaffarpur and the neighbouring districts of Vaishali and East and West Champaran grow the GI-tagged Shahi litchi that makes Bihar India's top litchi-producing state, close to 40 percent of the national crop, while the state has quietly become the country's third-largest maize producer on the back of a fast-expanding rabi maize season, and its cane belt still ranks among India's top sugarcane-producing states. All of it sits on a river system, the Kosi, Gandak and Bagmati among them, that decides whether a north Bihar farmer's season survives intact. This page's live weather, AQI and fuel numbers matter very differently depending on who's reading: a Muzaffarpur litchi grower checking a March heat advisory before flowering, a Kosi-belt farmer near Supaul watching the river gauge before an embankment gives way, a Patna commuter checking the evening rain forecast, a Gaya or Bhojpur outdoor worker deciding whether to start a shift before dawn to beat the May heat.

North Bihar's Floods, Aurangabad's Heat: Bihar's Two Real Risks

Bihar's defining hazard is the river system that gives north Bihar its nickname: the Kosi is widely called the "Sorrow of Bihar" for repeatedly shifting course and breaching its own embankments. In the last week of September 2024, the swollen Kosi, Bagmati and Gandak breached embankments at seven points across north Bihar; disaster officials linked 52 deaths to drowning, lightning and road accidents on a single day, September 24, and two days later a separate tragedy killed at least 46 people, 37 of them children, when floodwater engulfed Jivitputrika festival bathing spots across 15 districts. By early October, close to 1.5 million people across 17 districts, including Supaul, Saharsa, Darbhanga and both Champarans, were affected, and residents called it the worst Kosi flooding since 1968. Heat is the other real threat. Aurangabad touched 47.7°C on May 28, 2024, Bihar's highest temperature on record, and Gaya followed a day later at 47.4°C, breaking a mark that had stood since 1896; heatstroke deaths were still climbing a week on, with the state's own tally at 19 by May 31 (12 of them in Aurangabad) while several newspaper counts put the toll considerably higher as the heatwave rolled into June. A year earlier, in June 2023, heat killed 12 people statewide, 6 of them in Bhojpur alone, as nearby Sheikhpura touched 44.2°C.

How to Use Bihar's Data for Daily Decisions

Litchi growers in Muzaffarpur, Vaishali and West Champaran should track the March-to-April temperature and rainfall outlook closely, since the 2024 season lost up to 70 percent of the crop in parts of Muzaffarpur to a combination of early heat, unseasonal rain and the stink bugs that thrive in the gap between the two. Farmers and riverside households across the Kosi, Gandak and Bagmati belt, Supaul, Saharsa, Madhubani, Darbhanga and both Champarans especially, should treat any river-level bulletin from the state Water Resources Department as seriously as a rainfall forecast between June and September, since an embankment breach can flood a village faster than local rain alone would suggest. Outdoor workers and daily-wage labourers in Gaya, Bhojpur and Aurangabad, the districts that have repeatedly recorded the state's worst heatstroke tolls, should shift physical work to before 8am through May and June rather than wait for an official heatwave alert. Patna commuters should check the evening rain forecast during the monsoon months, when low-lying stretches of the city have repeatedly waterlogged within an hour of a heavy burst. Anyone travelling to a Chhath Puja ghat along the Ganga in October or November should check both the river level and the AQI before heading out, since the festival draws enormous riverside crowds right as north Bihar's flood season is only just receding.

Bihar's Seasonal Calendar

Monsoon normally reaches Patna around June 19, a few days after it first arrives in Bihar's eastern districts, and holds through September, delivering the bulk of the state's roughly 1,270mm average seasonal rainfall. Flood season runs alongside it, June to September, but the real danger window is typically late August through September and into early October, when upstream rain in Nepal's catchment sends the Kosi, Gandak and Bagmati toward their highest levels of the year. Heat season runs March to June, peaking in May, when Aurangabad, Gaya, Bhojpur and Sheikhpura have all posted some of the state's hottest readings in recent summers. Litchi harvest runs a brief, high-stakes window in May and June, right at the tail of peak heat, which is exactly why a hot, dry March or a wet, humid April can cost growers a season's income before a single fruit is picked. Chhath Puja, Bihar's largest festival, falls in late October or November and centres on river and pond banks across the state, drawing crowds just as floodwaters from the monsoon are typically receding. Winter, December to February, is short, mild and the state's most stable stretch for travel and outdoor events, though dense fog can still settle over Bihar's northern districts and disrupt early-morning road and rail traffic.

Bihar vs Nearby States: Weather & Data Comparison

Uttar Pradesh, Jharkhand and West Bengal figures are reused from this site's own already-published pages for internal consistency; Bihar figures are freshly sourced. Treat this as a broad reference, not a single-source dataset.