Early monsoon arrival expected in Delhi, 10 days before schedule!
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The southwest monsoon, a lifeline for India’s agriculture and economy, is set to make an early arrival in Delhi in 2025, bringing much-needed relief from the scorching summer heat. Typically arriving around June 30, the monsoon is expected to reach the national capital between June 20 and June 25, according to the India Meteorological Department (IMD) and other weather forecasts. This early onset, potentially 7 to 10 days ahead of schedule, is driven by favorable atmospheric and oceanic conditions. In this blog, we dive into the details of this early monsoon arrival, its causes, impacts, what Delhiites can expect in the coming weeks, and a historical perspective on monsoon arrivals in Delhi.
Why Is the Monsoon Arriving Early in Delhi?
Favorable Atmospheric Conditions
The early arrival of the monsoon in Delhi is linked to several large-scale atmospheric and oceanic phenomena. The IMD has reported that conditions in the Bay of Bengal and Arabian Sea are conducive to a faster northward progression of the monsoon. Key factors include:
- Madden-Julian Oscillation (MJO): The MJO, a global weather phenomenon, enhances rainfall during its favorable phase. In 2025, the MJO has been active over the Indian Ocean, boosting monsoon activity.
- Strong Somali Jet: This low-level wind band, originating near Mauritius and Madagascar, strengthens monsoon winds as it reaches the Arabian Sea. A robust Somali jet has been observed this year, aiding the monsoon’s early advance.
- Reduced Snow Cover in the Himalayas: Lower snow cover in the Himalayan region correlates with stronger monsoon activity, as it allows more solar heating of the land, creating a stronger low-pressure system that pulls monsoon winds northward.
- Mascarene High: A high-pressure area in the south Indian Ocean, the Mascarene High has been particularly strong in 2025, driving moisture-laden winds toward India.
Early Monsoon Onset in Kerala
The monsoon’s journey begins with its onset over Kerala, which occurred on May 24, 2025, eight days earlier than the usual June 1. This marked the earliest onset since 2009, when it arrived on May 23. The IMD noted that 60% of 14 key meteorological stations in southern India reported rainfall of 2.5 mm or more for two consecutive days, meeting the criteria for monsoon onset. Strong westerly winds and low outgoing longwave radiation (OLR) values further confirmed the early start.
This early onset in Kerala set the stage for a rapid northward progression, with the monsoon covering southern and central India ahead of schedule. Posts on X indicate that the monsoon is expected to reach East Uttar Pradesh, East Madhya Pradesh, and parts of central India by June 19–21, paving the way for its arrival in Delhi shortly after.
Historical Monsoon Arrival Dates in Delhi
Monsoon Arrival from 2010 to 2024
To understand the significance of the early monsoon in 2025, it’s helpful to look at the historical arrival dates of the monsoon in Delhi over the past 15 years. The following table lists the monsoon onset dates from 2010 to 2024, showcasing the variability in arrival times:
| Year | Monsoon Arrival |
|---|---|
| 2024 | 28 June |
| 2023 | 25 June |
| 2022 | 30 June |
| 2021 | 10 July |
| 2020 | 25 June |
| 2019 | 5 July |
| 2018 | 28 June |
| 2017 | 2 July |
| 2016 | 2 July |
| 2015 | 25 June |
| 2014 | 3 July |
| 2013 | 16 June |
| 2012 | 7 July |
| 2011 | 8 July |
| 2010 | 5 July |
The data shows that the monsoon typically arrives in Delhi between late June and early July, with the earliest recorded onset in this period being 16 June 2013 and the latest on 10 July 2021. The projected arrival between June 20 and June 25, 2025, aligns closely with the earliest historical onset, indicating an unusually early start this year.
Monsoon’s Progress and Delhi’s Weather Outlook
Current Weather in Delhi
As of June 13, 2025, Delhi is experiencing intense heat, with maximum temperatures exceeding 40°C for several days. The IMD has forecasted a maximum temperature of around 44°C in the coming days, with heatwave conditions likely until the monsoon arrives. However, light dust storms and isolated thunderstorms are expected to provide slight relief starting June 14, with some areas potentially seeing light rain by June 15.
Monsoon’s Arrival in Delhi
The IMD’s extended-range forecast suggests that the monsoon will resume its northward advance after a brief pause, reaching Delhi between June 20 and June 25. This aligns with posts on X, where weather enthusiasts and forecasters predict a monsoon onset around June 20, followed by rapid coverage of northern India by June 22.
Delhiites can expect:
- Initial Showers: Light to moderate rainfall accompanied by thunderstorms and gusty winds (30–60 kmph) as the monsoon sets in.
- Temperature Drop: The arrival of monsoon rains will lower maximum temperatures from the mid-40s to the low-30s, offering significant relief from the heat.
- Increased Humidity: While temperatures will decrease, humidity levels will rise, creating muggy conditions typical of the monsoon season.
Rainfall Forecast for Delhi
The IMD has projected above-normal rainfall for the Haryana-Chandigarh-Delhi region, with Delhi expected to receive 114% of its long-period average (LPA) of 640.4 mm for the monsoon season (June–September). This forecast is encouraging for water availability and agriculture in the region.
May 2025 was already exceptionally wet for Delhi, with the city recording 186.4 mm of rainfall—nearly seven times the monthly average of 25.1 mm—due to intense thunderstorms and summer storms. This wet pre-monsoon period, combined with the early monsoon onset, suggests a robust rainy season ahead.
Impacts of an Early Monsoon in Delhi
Positive Impacts
- Relief from Heat: The early monsoon will provide respite from the ongoing heatwave, which has pushed temperatures to 42.3°C in Delhi this season. Cooler temperatures will improve living conditions and reduce heat-related health risks.
- Agricultural Benefits: An early monsoon allows farmers in Delhi and surrounding areas to sow crops like rice, pulses, and vegetables earlier, potentially boosting yields. Surplus soil moisture from pre-monsoon rains further supports early sowing.
- Water Replenishment: Delhi relies on monsoon rains to recharge groundwater and fill reservoirs. Above-normal rainfall could help alleviate water scarcity issues in the capital.
- Economic Boost: A strong monsoon supports India’s agricultural sector, which employs 42.3% of the population and contributes 18.2% to GDP. Timely rains in Delhi and northwest India will benefit the regional economy.
Challenges
- Flooding and Waterlogging: Delhi’s infrastructure often struggles with heavy monsoon rains, leading to waterlogging in low-lying areas and traffic disruptions. The early onset may catch civic authorities off guard if drainage systems are not prepared.
- Health Risks: Increased humidity and stagnant water can lead to a rise in vector-borne diseases like dengue and malaria. Public health measures will be crucial to mitigate these risks.
- Transportation Disruptions: Thunderstorms and heavy rains may affect road and air travel, requiring proactive measures from authorities to ensure safety and connectivity.
Preparing for the Monsoon in Delhi
For Residents
- Home Maintenance: Check roofs and drainage systems to prevent leaks and waterlogging.
- Health Precautions: Stock up on mosquito repellents and stay hydrated to cope with humidity.
- Travel Planning: Monitor weather updates and avoid travel during heavy rain or thunderstorms.
For Authorities
- Infrastructure Readiness: Clear drainage systems and reinforce flood-prone areas to prevent waterlogging.
- Public Awareness: Disseminate weather alerts through social media, APIs, and traditional media, as emphasized by the IMD’s efforts in early warning systems.
- Health Campaigns: Launch initiatives to control vector-borne diseases and ensure adequate medical supplies.
The Bigger Picture: Monsoon 2025 Across India
The early monsoon onset in Kerala and its rapid progression signal a robust monsoon season for India. The IMD’s long-range forecast predicts above-normal rainfall (106% of LPA) for the country, with northwest India expected to receive normal to above-normal rainfall. Central India, the monsoon core zone, is projected to see particularly heavy rains, while northeast India may experience below-normal rainfall.
This forecast is a boon for India’s economy, as the monsoon accounts for 75% of the country’s annual rainfall. Adequate rainfall will support agriculture, replenish reservoirs, and boost hydroelectric power generation. However, the early onset and above-normal rainfall also raise concerns about flooding in vulnerable regions, underscoring the need for disaster preparedness.
The early arrival of the monsoon in Delhi in 2025, expected between June 20 and June 25, is a significant event, marking one of the earliest onsets in recent years, comparable to the 2013 arrival on June 16. This early monsoon promises relief from the summer heat and supports agricultural and economic activities. However, it also poses challenges that require proactive preparation from residents and authorities alike. By staying informed through reliable sources like the IMD (mausam.imd.gov.in) and taking necessary precautions, Delhi can make the most of this early monsoon season.
As the monsoon clouds gather over the capital, Delhiites can look forward to cooler days, lush greenery, and the rhythmic patter of rain—a reminder of nature’s vital role in shaping life in India.
Sources: India Meteorological Department (mausam.imd.gov.in), India Today, Hindustan Times, CNBC TV18, Indian Express, Reuters, Business Standard, Times of India, and posts on X.
