Bihar Temperature & Weather History

Historical Climate Data & Weather Trends (1981-2025)

Comprehensive climate analysis across 37 districts in Bihar, India

Bihar Climate Overview

Bihar, India has an average annual temperature of 26.0°C, approximately 1049mm of rainfall per year, and average humidity of 56%. Temperatures range from 4.5°C in Siwan to 47.0°C in Buxar. This page covers 45 years of historical climate data (1981–2025) across all 37 districts, sourced from NASA POWER — with monthly charts, yearly trends, and a full district comparison table.

☀️

Quick Climate Facts

(1981 - 2025)

State Avg

🌡️

Average Temperature

26.0°C

State Avg

❄️

Min Temperature

5.2°C

State Avg

🔥

Max Temperature

45.5°C

State Avg

🌧️

Average Rainfall

2.9 mm/day

State Avg

💧

Average Humidity

56.1%

State Avg

💨

Average Wind Speed

2.0 m/s

State Avg

📍

Number of Districts

37

State Avg

📅

Data Period

1981-2025

📊Monthly Climate Averages for Bihar

📖Understanding Bihar's Climate Patterns

These charts show monthly temperature and rainfall patterns for Bihar, averaged across all 37 districts and 45 years of data. Use them to understand seasonal shifts — when monsoon arrives, which months are hottest, and how humidity peaks align with rainfall.

🌡️Temperature Patterns

Monthly averages · 1981–2025 climate normals · °C

🌧️Rainfall Distribution

Monthly rainfall · 1981–2025 seasonal trends · mm/month

📈Long-term Climate Trends in Bihar (1981-2025)

🌍Climate Change and Historical Weather Trends

This chart tracks how Bihar's climate has changed from 1981 to 2025. Switch between Temperature, Rainfall, and Humidity tabs to spot long-term trends. Use the year range buttons to zoom into recent decades or view the full 45-year picture.

🌡️Yearly Temperature Trends(2016–2025)

Annual temp trends · 1981–2025 · °C

🗺️Climate Diversity Across Bihar

Across its 37 districts, Bihar has significant climate variation. Siwan is the coolest district with average lows of 4.5°C, while Buxar reaches average highs of 47.0°C. Kishanganj is the wettest district at 4.1 mm/day. These differences are driven by altitude, proximity to water bodies, and geography.

Coldest District
Siwan
4.5°C min
Hottest District
Buxar
47.0°C max
Wettest District
Kishanganj
4.1 mm/day

📍Weather Data for All 37 Districts in Bihar

Click any district to view its full 45-year weather history — monthly patterns, yearly trends, and extreme records. Use search to find a specific district quickly.

Show:
DistrictAvg TempMin TempMax TempRainfallHumidity
Araria25.6°C5.9°C43.7°C3.3 mm/day60.2%
Aurangabad25.9°C5.2°C46.3°C2.9 mm/day54.6%
Banka25.8°C5.4°C45.0°C2.9 mm/day59.0%
Begusarai26.1°C5.1°C45.4°C2.8 mm/day56.7%
Bhagalpur25.8°C5.4°C45.0°C2.9 mm/day59.0%
Bhojpur26.3°C4.7°C46.8°C2.7 mm/day53.6%
Buxar26.5°C4.9°C47.0°C2.5 mm/day52.0%
Darbhanga26.1°C5.0°C45.7°C2.9 mm/day54.9%
Gaya26.2°C4.8°C46.7°C2.8 mm/day55.1%
Gopalganj26.0°C4.7°C45.8°C2.9 mm/day53.8%

Showing 1 to 10 of 37 districts

❓Frequently Asked Questions

The average annual temperature in Bihar is 26.0°C based on 45 years of historical climate data from 1981 to 2025. Temperatures vary significantly across the state's 37 districts, ranging from an average minimum of 5.2°C to an average maximum of 45.5°C.
Buxar is the hottest district in Bihar, with an average maximum temperature of 47.0°C and an average annual temperature of 26.5°C. This makes it one of the warmest areas in the state throughout the year.
Siwan is the coldest district in Bihar, with an average minimum temperature of 4.5°C and an average annual temperature of 26.2°C. Winter temperatures in this district can drop significantly below the state average.
Bihar receives an average of 2.9 mm/day of rainfall, which translates to approximately 1049 mm annually. Rainfall varies considerably across districts, with Kishanganj being the wettest at 4.1 mm/day and Buxar being the driest at 2.5 mm/day.
Kishanganj receives the highest rainfall in Bihar, averaging 4.1 mm/day or approximately 1492 mm per year. This district experiences significantly more precipitation compared to the state average, making it ideal for water-intensive agriculture.
The average relative humidity in Bihar is 56.1%. Humidity levels vary across the state, with Kishanganj having the highest average humidity at 63.0% and Buxar having the lowest at 52.0%. These variations affect local climate comfort and agricultural practices.
This comprehensive weather dataset covers all 37 districts in Bihar. Each district's climate data has been collected from NASA POWER (Prediction of Worldwide Energy Resources) and includes 45 years of historical records from 1981 to 2025. The state-level statistics presented are calculated by averaging data across all districts.
All weather and climate data for Bihar is sourced from NASA POWER (Prediction of Worldwide Energy Resources), which provides reliable meteorological data from NASA research. The data is based on the MERRA-2 Reanalysis with a spatial resolution of 0.5° x 0.625° and covers the period from 1981 to 2025. This ensures high-quality, scientifically validated climate information aggregated across all 37 districts in the state.
This comprehensive weather history can help farmers and agricultural planners in Bihar make informed decisions about crop selection, planting schedules, and irrigation planning. The data shows that Kishanganj receives the most rainfall (4.1 mm/day), making it suitable for water-intensive crops, while Buxar receives less rainfall (2.5 mm/day) and may require more irrigation. Temperature variations across districts help determine suitable growing seasons for different crops. The 45-year dataset also helps identify long-term climate trends that may require adaptation in farming practices.
Bihar shows significant climate diversity across its 37 districts. Temperature varies from 4.5°C in Siwan to 47.0°C in Buxar. Rainfall patterns range from 2.5 mm/day in Buxar to 4.1 mm/day in Kishanganj. This diversity is influenced by factors such as altitude, proximity to water bodies, and geographical features, creating distinct microclimates within the state.

📚 Data Source & Methodology

All climate data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing satellite-derived meteorological data used globally by researchers and agricultural planners. State-level figures are calculated by averaging data across all 37 districts in Bihar.

Parameters included:
  • Temperature (Min, Max, Average)
  • Precipitation (Rainfall)
  • Relative Humidity
  • Wind Speed
Data specifications:
  • Temporal Resolution: Monthly
  • Spatial Resolution: 0.5° x 0.625°
  • Source: MERRA-2 Reanalysis
  • Coverage: 1981-2025 (45 years)

Historical weather data for Bihar, India • Data: NASA POWER • 1981-2025 • Covering 37 districts