Unprecedented December Rainfall in Delhi: Breaking 101-Year Records and Implications
Delhi, the capital city of India, has recently experienced an unprecedented amount of rainfall in December 2024, shattering a 101-year record for the highest single-day rainfall in the month. This unusual weather event has significant implications for the city's infrastructure, daily life, and long-term climate trends.
Background Information
December is typically one of the driest months in Delhi, with usual rainfall amounts being quite light. According to the India Meteorological Department (IMD), Delhi usually sees about 8 mm of rain during the entire month of December. This average is spread over half a day, making the recent rainfall even more remarkable[1][3][4].
Key Statistics and Data
The rainfall on December 28, 2024, was particularly noteworthy. Delhi recorded 41.2 mm of rain in the 24 hours ending at 8:30 am on Saturday, marking the highest single-day December rainfall since December 3, 1923, when 75.7 mm of rain was recorded. This event surpasses the typical December rainfall by more than five times[2][4][5].
Monthly Rainfall Records
This significant rainfall made December 2024 the fifth-highest in terms of monthly rainfall since records began in 1901, with a total of 42.8 mm of rain for the month. The 24-hour cumulative rainfall ending at 8:30 am on Saturday was the second-highest since 1901 at the Safdarjung weather station[1][2][4].
Historical Context
Previous high rainfall records in December include 77.2 mm in 1901, 71.8 mm in 1997, 69.5 mm in 1967, and 68.1 mm in 1936. The recent rainfall has surpassed these historical figures, highlighting the unusual nature of this weather event. It is worth noting that December 2024 saw six rainy days, a stark contrast to the previous years where rainfall was almost negligible. For instance, December 2023 and 2022 saw no rainfall, while 2021 recorded 9.6 mm, and 2020 recorded just 1.6 mm[4].
Expert Opinions and Quotes
The unusual weather patterns can be attributed to the interaction of various weather systems. An IMD scientist explained:
"The interaction between a very active western disturbance and a cyclonic circulation on the east, along with a few other factors, has brought about this unusual weather. November and December are the two driest months in Delhi. During these months, it is usually a western disturbance that brings rain to the capital. It is the different weather systems clashing that lead to heavy downpours"[1][3][4].
Mahesh Palawat, vice president at Skymet, further elaborated on the conditions leading to the dense fog that followed the rainfall:
"The dense fog will form because of the moisture from the moderate spells of widespread rain that Delhi experienced on Friday, due to a western disturbance interacting with easterly winds. There might be some wind of moderate speed 8-9 kmph, aiding fog formation"[5].
Related Developments
The heavy rainfall was accompanied by gusty winds and caused significant disruptions across the city. Here are some key developments:
Infrastructure and Daily Life
- The rainfall caused significant disruptions, including uprooted trees in areas such as Palam, Safdarjung, Lodi Road, and Mehrauli. A road caved in at Sector-9, RK Puram, causing a motorcycle and a car to fall into the cavity[1].
- Waterlogging and traffic snarls were reported in many areas across the city, with the Municipal Corporation of Delhi Central Control Room receiving a total of 13 complaints, nine for waterlogging and four for fallen trees[4].
- The heavy rain also led to power outages in some areas, further complicating daily life for residents.
Weather Alerts
- The weather department issued a yellow alert for the weekend, predicting light to moderate rain and thunderstorms over Northwest and Central India, including the Delhi-NCR region[1][2][4].
- An orange alert was issued for Sunday due to the possibility of dense fog in most places and very dense fog in isolated places. This alert system helps in preparing the public and authorities for potential disruptions[5].
Air Quality
- The heavy rainfall and subsequent wind conditions led to an improvement in air quality, with the Air Quality Index (AQI) recorded at 139-152, categorizing it as 'moderate'. This is a significant improvement from the 'very poor' category that Delhi often experiences during the winter months[1][2][4].
- The improvement in air quality was also attributed to strong, consistent winds in the first half of the month. December 2024 marked Delhi's cleanest December air since the introduction of the AQI system in 2015, with an average AQI of 294 for the month[4].
Industry Impact
The heavy rainfall and subsequent fog conditions have significant implications for various industries and daily activities:
Transportation
- The IMD advised citizens to be on watch for dense fog, which could affect road and air travel. This warning is crucial for commuters and travelers, as dense fog can significantly reduce visibility and increase travel times. Airlines and road transport services were advised to take necessary precautions to ensure safety[5].
Daily Activities
- The improvement in air quality, though temporary, provided some relief from the typically poor air quality conditions in Delhi during the winter months. However, the overall impact on daily activities, such as school closures and work disruptions, was minimal but notable. Some schools and offices experienced delays or closures due to the heavy rain and subsequent disruptions[1][2][4].
Agricultural Impact
- The rainfall, while disruptive in urban areas, can have positive effects on agricultural activities. The moisture from the rain can help in replenishing soil moisture, which is beneficial for winter crops. However, the timing and intensity of the rain need to be carefully monitored to avoid any adverse effects on crop health[3].
Future Implications
The recent rainfall event and its associated weather patterns have several future implications:
Climate Change
- The long-term implications of such unusual weather patterns could include more frequent and intense weather events due to climate change. Sunita Narain, director general of the Centre for Science and Environment, noted:
"Because of climate change, you will get more extreme rain events, which means more rain in a fewer number of rainy days, rainy hours. If you look at the data from across India, you will find that many weather stations are already reporting that they are breaking the record of 24-hour rainfall, which means that a city, a region, can get its annual rain, as much as a whole year's rain, in a matter of a few days or even one day"[2][5].
- This trend suggests that cities need to be better prepared for such extreme events through improved infrastructure and emergency response systems.
Cold Wave and Future Weather Systems
- The weather department predicted that cold wave conditions are likely to commence over north India from Sunday, with a significant drop in minimum temperatures expected across several regions. Strong northwesterlies are likely to bring in cold air from the mountains, leading to a sharp dip in temperatures[5].
- Another western disturbance is expected around January 1, but it is not forecasted to bring significant rain to the region. This highlights the ongoing dynamic nature of weather patterns in the region and the need for continuous monitoring and preparedness[1][3][4].
Urban Planning and Climate Resilience
The recent rainfall event underscores the importance of integrating climate resilience into urban planning and policy-making. Here are some key considerations:
Infrastructure Adaptation
- Cities need to invest in infrastructure that can withstand extreme weather events. This includes improving drainage systems, reinforcing roads, and ensuring that public spaces are designed to handle heavy rainfall and subsequent flooding.
- The use of green infrastructure, such as urban parks and green roofs, can also help in mitigating the effects of heavy rainfall by absorbing excess water and reducing runoff.
Emergency Preparedness
- Developing robust emergency response plans is crucial. This includes setting up early warning systems, conducting regular drills, and ensuring that emergency services are equipped to handle the aftermath of such events.
- Public awareness campaigns can also play a significant role in preparing citizens for extreme weather events, helping them to take necessary precautions and stay safe.
Climate-Resilient Policies
- Policy-makers need to incorporate climate change projections into urban planning. This involves developing policies that promote sustainable development, reduce greenhouse gas emissions, and enhance the city's ability to adapt to changing climate conditions.
- Collaborative efforts between local, state, and national governments are essential in addressing the broader implications of climate change and ensuring that cities are equipped to handle future challenges.
Conclusion
The unprecedented December rainfall in Delhi highlights the increasing unpredictability of weather patterns, which can be attributed to both specific weather system interactions and broader climate change trends. As cities like Delhi continue to face such extreme weather events, it becomes imperative to focus on climate-proofing infrastructure and adapting to these new climate realities.
The immediate effects of the rainfall, including disruptions to daily life and improvements in air quality, serve as a reminder of the complex interplay between weather, infrastructure, and human activities. By understanding and preparing for such events, we can build more resilient cities that can adapt to the challenges of a changing climate.
In conclusion, the December 2024 rainfall in Delhi is a significant event that underscores the need for proactive measures to address climate change and its associated weather extremes. By integrating climate resilience into urban planning, improving emergency preparedness, and developing climate-resilient policies, we can mitigate the impacts of such extreme weather events and build a more sustainable future for our cities.
