Residents of Chandigarh, Punjab and Haryana will need to brace for a drier-than-usual monsoon this year. The India Meteorological Department (IMD) on Tuesday released its first-stage, long-range forecast for the 2026 southwest monsoon season, predicting below-normal rainfall over most parts of Punjab and Haryana, including Chandigarh, during the June-to-September period.The forecast, issued by the Meteorological Centre, Chandigarh, puts the national seasonal rainfall at 92 per cent of the Long Period Average (LPA) – with a model error of plus or minus five per cent – placing it firmly in the below-normal bracket of 90 to 95 per cent. The LPA for seasonal rainfall over the country as a whole, calculated for the reference period 1971 to 2020, stands at 87 cm.For Chandigarh Tricity and surrounding states, the numbers are equally stark. The LPA for seasonal rainfall (June to September) over Punjab, Haryana and Chandigarh stands at 439.8 mm, 426.0 mm and 844.9 mm respectively – and IMD forecasts below-normal rainfall across all three this season.DEFICIENT RISK IS REALThe five-category probabilistic forecast paints a cautionary picture. The probability of deficient rainfall – defined as less than 90 per cent of LPA – has been pegged at 35 per cent, more than double its climatological probability of 16 per cent.The below-normal category (90 to 95 per cent of LPA) carries a forecast probability of 31 per cent, against its climatological norm of 17 per cent. Together, the two adverse categories account for 66 per cent of the probability.At the other end, the chances of normal rainfall (96 to 104 per cent of LPA) stand at only 27 per cent – well below the climatological probability of 33 per cent. The probabilities for above-normal and excess rainfall have fallen sharply to six per cent and one per cent respectively, against their climatological benchmarks of 16 per cent and 17 per cent.EL NIÑO THREAT LOOMSIMD has flagged the evolving global climate signals as a key driver behind the subdued outlook. At present, weak La Niña-like conditions are transitioning to ENSO-neutral conditions over the equatorial Pacific. However, the Monsoon Mission Climate Forecast System (MMCFS) suggests that El Niño conditions could develop during the southwest monsoon season itself – a scenario historically associated with reduced rainfall over the subcontinent.On the Indian Ocean side, neutral Indian Ocean Dipole (IOD) conditions currently prevail, but climate models indicate that positive IOD conditions are likely to develop towards the end of the monsoon season. A positive IOD can partially compensate for El Niño’s suppressive effect on monsoon, though its onset towards season-end limits its benefit.Northern hemisphere snow cover during January-March 2026 was slightly below normal – a factor IMD notes has a general inverse relationship with subsequent southwest monsoon rainfall.SPATIAL SPREADThe spatial distribution of probabilistic forecasts indicates that below-normal seasonal rainfall is the most likely outcome across a large part of the country. Exceptions include certain areas over the Northeast, Northwest extremities and South Peninsular India, where normal to above-normal rainfall is likely.WHAT COMES NEXTThis is the first of a two-stage forecasting exercise. IMD will issue the second-stage forecast around May end, which will include an update on seasonal rainfall projections along with probabilistic forecasts for four broad homogeneous regions of the country – including Northwest India, which encompasses Punjab, Haryana and Chandigarh.A forecast for the second half of Monsoon 2026 will also be issued at the end of July.