India’s Record-Breaking Warm Year

May 2, 2025

Recently, the India Meteorological Department (IMD) reported that 2024 was the warmest year in India’s recorded history. The average surface temperature anomaly was +0.65°C above the long-term average. However, there are concerns that actual warming may have exceeded the critical threshold of 1°C. This discrepancy arises from changes made to the Long Period Average (LPA) used by IMD for temperature comparisons.

Long Period Average (LPA)

The LPA is crucial for assessing climate trends. It is defined as the average temperature over a 30-year period. IMD has revised the LPA multiple times over the past two decades. This has implications for how warming is reported. Each revision has resulted in a higher baseline temperature, making current anomalies appear smaller than they are.

Changes in Temperature Reporting

Historically, IMD used the 1961-1990 average as the LPA. In 2016, it shifted to the 1971-2000 average. The LPA was updated again in 2019 to the 1981-2010 average, and most recently in 2024 to the 1991-2020 average. This shifting baseline means that the reported anomalies for previous years have been adjusted downwards . For example, the anomaly for the year 2010 has decreased from +0.93°C to just +0.39°C when compared to the latest LPA.

Transparency Issues in Data Reporting

IMD’s annual summaries do not provide the actual recorded temperatures or the LPA temperatures, only the anomalies. This lack of transparency complicates the ability to track trends accurately. Critics argue that this practice raises questions about the validity of the reported data.

Extreme Weather Events in 2024

Regardless of how warming is measured, the impacts of climate change are evident. In 2024, India faced extreme weather events on 322 days of the year, affecting nearly 88% of the country. This is an increase from previous years, denoting a worrying trend. The human cost has been substantial, with 3,472 fatalities attributed to extreme weather events in 2024.

Impact on Agriculture

The agricultural sector has also been severely impacted by extreme weather. In 2024, over 4.07 million hectares of cropped land were affected, marking an 84% increase from the previous year. Every region of India has experienced more extreme weather days, with Central India recording the highest number.