Kathmandu, Oct. 15: On May 8, 2026, the Department of Hydrology and Meteorology (DHM) released its National Seasonal Outlook for Monsoon Season 2026, forecasting weaker than normal monsoon across most parts of the country, which officially runs from June 1 to September 30.
However, after the monsoon withdrew from the country, seasonal rainfall was found to be near normal, reaching 94.5 per cent of the average during this four months period.Weather forecasts help people prepare for rainfall, floods, landslides, droughts and other weather-related hazards. However, forecasts do not always match 100 per cent.
Due to complex geography and limited weather observation stations in remote areas make accurate forecasting difficult. Seasonal forecasts are even more challenging than short-term predictions.
Weather conditions vary greatly across the country, from the Tarai to the high Himalayas, due to differences in altitude, slopes and valleys. Even nearby areas can receive different amounts of rainfall depending on their location, sunlight and exposure to weather systems
Nepal has made considerable progress in weather forecasting over the past 15 to 20 years. However, significant challenges remain, particularly in predicting weather at the local level and providing reliable seasonal outlooks.
Why does Nepal need more weather stations?
Accurate forecasting depends on reliable observations. Meteorologists use data collected from weather stations, satellites, radar systems, weather balloons and other instruments to understand atmospheric conditions and predict how they will change, said Dr. Madan Sigdel, Associate Professor at the Central Department of Hydrology and Meteorology, Tribhuvan University (TU), Kirtipur.
However, country’s observation network remains limited in some areas, particularly in the high mountains. Collecting weather data becomes increasingly difficult at elevations above 3,000 metres because many locations are remote and difficult to access. As a result, observation stations cannot cover all the areas where data are needed.
The location of observation stations is also important. Because Nepal's terrain is highly varied, measurements taken at one location may not accurately represent conditions in nearby valleys or on different mountain slopes.
Weather forecasting requires information not only about conditions at the Earth's surface but also about the atmosphere above it.
Weather balloons provide information about atmospheric conditions at different heights. Radar systems help meteorologists observe precipitation and track weather systems, while satellite images provide a broader view of atmospheric developments.
Dr. Sigdel said Nepal's upper-atmosphere observation capacity is limited. Although radar systems have been installed in locations including Palpa, Udayapur and Surkhet, their data need to be available and used effectively for forecasting.
Meteorologists sometimes use atmospheric observations from neighbouring regions, including Patna in India and the Tibetan Plateau. However, these data may not always adequately represent the conditions affecting Nepal.
Why can one place receive heavy rain while another remains dry?
Weather can vary significantly even within the same city or municipality. This is known as a microclimate, in which local conditions differ from the surrounding area.
Changes in land use can further influence local temperatures and weather conditions. When agricultural land or green spaces are replaced by buildings and concrete surfaces, the amount of heat absorbed and retained by the land changes.
The influence of El Niño on Nepal's monsoon cannot be determined simply by observing changes in sea-surface temperatures in the central and eastern Pacific Ocean. The effects of El Niño on South Asian weather depend on atmospheric connections, often described as teleconnections, through which changes in one region influence atmospheric circulation elsewhere.
These connections take time to develop and do not necessarily produce immediate or uniform effects in Nepal.
Is climate change making weather forecasts less accurate?
Climate change and the accuracy of weather forecasts are related issues, but they should not be treated as the same problem. The growing importance of local weather variations, changes in land use and the need to account for different atmospheric processes when developing forecasts.
To determine whether climate change contributed to a specific forecasting error, scientists would need to examine the observed weather, the forecast models and the relevant atmospheric conditions.
Climate change, local environmental changes and the limitations of observation networks are therefore issues that need to be examined carefully rather than assuming that every unexpected weather event is caused by climate change.
Has weather forecasting in Nepal improved?
Despite these challenges, Nepal's forecasting capacity has improved considerably compared with 15 to 20 years ago.
The country now has greater access to satellite images, automated weather stations, numerical weather prediction models and data from other countries. These developments have strengthened the information available to meteorologists, Dr. Sigdel said.
Nevertheless, forecasting is not expected to be 100 per cent accurate, even in countries with advanced technologies.
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