PARLIAMENT QUESTION: ACCURACY OF WEATHER FORECASTING SYSTEMS
PARLIAMENT QUESTION: ACCURACY OF WEATHER FORECASTING SYSTEMS
The India Meteorological Department (IMD) has been following a seamless forecasting strategy for monsoonal rainfall. As per this strategy, it issues forecasts and warnings on different time scales and for different spatial scales. Nowcasting- up to six hours for all types of severe weather at all districts and around 1200 stations. Short to medium range (up to 7 days) forecasts for rainfall over cities, blocks, districts, and meteorological subdivisions. Extended range (up to 4 weeks) forecasts for 36 meteorological sub-divisions. Monthly and seasonal long-range forecasts for rainfall for the whole country and for homogenous region.
The latest assessment of the accuracy of its seasonal long range for Southwest Monsoon in the current year 2025 shows it was highly accurate and the forecast, issued in April 2025, for the southwest monsoon (June-September) rainfall over the country as a whole was 105% of long period average (LPA) while the actual season rainfall for the country as a whole was 108 % of LPA and it was within errors range of the forecast issued. The spatial probability forecasts were also largely accurate across most regions of the country. Similarly, the monthly rainfall forecasts closely matched the observed values and remained within the forecast limits.
The latest assessment of Heavy rainfall Forecast Performance shows in 2025, the heavy rainfall forecast demonstrated high skill, with Probability of Detection of 0.85, indicating it was in overall accuracy.
IMD has adopted a new strategy for monthly and seasonal forecasting since 2021 based on the Multi-Model Ensemble (MME) approach. The strategy utilizes coupled global climate models (CGCMs from various global climate prediction and research centers, including IMD’s Monsoon Mission Climate Forecasting System (MMCFS). The performance of IMD’s seasonal forecasting system has shown improvement following the adoption of the MME-based approach. The verification details of IMD’s seasonal forecasts for All India Summer Monsoon Rainfall for the period 2021 to 2025 are given below:
Year
ALL India Monsoon Rainfall (LPA)
Actual (%)
Forecast (%)
Remark
2021
99
101
Accurate
2022
106.5
103
Accurate
2023
95
96
Accurate
2024
108
106
Accurate
2025
108
106
Accurate
***Model error ± 4% of LPA
For seasonal and short-range weather prediction, IMD uses a range of advanced tools, models, and observation systems as part of its operational forecasting framework. Under the Mission Mausam project, already Bharat Forecast System (BharatFS), an advanced computer simulation model has been developed, and it has been operational at a very high spatial resolution of 6 km. It has also a capability to provide predictions of rainfall events up to 10 days, covering the short and medium range. Further, to support such high-resolution models running regularly, the Computing facilities have also been substantially increased to integrate voluminous data and to run meso-scale, regional, and global models at higher resolution. Recently, with the implementation of the High Power Computing Systems “Arunika” and “Arka”, the Ministry of Earth Sciences has enhanced its total computing power to 28 Peta FLOPS in 2025, a substantial increase from the previous capacity of 6.8 Peta FLOPS in 2014.
IMD is gradually integrating artificial intelligence (AI) and machine learning (ML)–based methods to enhance model performance, post-process model outputs, pattern recognition, bias correction, and probabilistic forecast interpretation. The weather observation system presently consists of 48 Doppler Weather Radars (DWRs) covering nearly 92% of the country, along with high-resolution satellite-based monitoring and around 6,300 rain gauge stations.
There are a total of 48 DWRs installed and operational in India. The locations where the DWR network has been established across the country are given in Annexure-1. This has helped IMD improve monitoring and forecasting of severe events such as cloudbursts, thunderstorms, lightning, and cyclones.
This information was submitted by Union Minister of State (Independent Charge) for Earth Sciences Dr. Jitendra Singh in Rajya Sabha on 12th February 2026.
Annexure-1
Locations of the current Doppler Weather Radar (DWR) network in the country:
S. No.
State
Location
Andhra Pradesh
Machilipatnam
Andhra Pradesh
Visakhapatnam
Andhra Pradesh
Sriharikota, ISRO
Assam
Mohanbari
Assam
Jorhat
Bihar
Patna
Chhattisgarh
Raipur
Goa
Goa
Gujarat
Bhuj
Himachal Pradesh
Jot
Himachal Pradesh
Murari Devi
Himachal Pradesh
Kufri
Karnataka
Mangalore
Kerala
Kochi
Kerala
VSSC, Thiruvananthpuram
(ISRO)
Madhya Pradesh
Bhopal
Madhya Pradesh
Silkheda (IITM)
Maharashtra
Mumbai
Maharashtra
Nagpur
Maharashtra
IITM Solapur
Maharashtra
Veravali
Maharashtra
Mumbai, Juhu (IITM)
Maharashtra
Mumbai, Panvel (IITM)
Maharashtra
Mumbai, Kalyan, Dombivali (IITM)
Maharashtra
Mumbai, Vasai, Virar (IITM)
Maharashtra
Mahabaleshwar (IITM)
Meghalaya
Cherrapunji (ISRO)
Odisha
Gopalpur
Odisha
Paradip
Punjab
Patiala
Rajasthan
Jaipur
Tamil Nadu
Chennai
Tamil Nadu
Karaikal
Tamil Nadu
NIOT Chennai
Telangana
Hyderabad
Tripura
Agartala
Uttarakhand
Lansdowne
Uttarakhand
Mukteshwar
Uttarakhand
Surkanda Devi
Uttar Pradesh
Lucknow
West Bengal
Kolkata
Jammu & Kashmir
Banihal Top
Jammu & Kashmir
Jammu
Jammu & Kashmir
Srinagar
Delhi
Ayanagar
Delhi
Palam
Delhi
HQ Mausam Bhawan
Ladakh
Leh