Unraveling Mumbai’s Unusual January Heat: Three Culprits

Introduction:
• Mumbai, typically known for its moderate climate, is currently grappling with an unexpected surge in temperatures this January. This anomaly has left residents puzzled and uncomfortable. The mercury soared to 35.7 degrees Celsius on January 12, marking the highest January day temperature in the past seven years. Meteorologists attribute this unusual warmth to three primary factors.
1. Influence of Moist South Easterly Winds and the Absence of Western Disturbances:
• Mumbai is currently under the influence of moist south easterly winds, a deviation from the dry northerly winds usually associated with winters. Sushma Nair, a scientist from IMD Mumbai, points out that the influx of these moist winds has led to increased temperatures and discomfort among the residents. The absence of Western Disturbances (WD), responsible for heavy snowfall in northern states, further impedes the arrival of cool northerly winds, preventing a significant temperature drop.
2. El Niño Effect:
• Meteorologists attribute the ongoing warmth to the El Niño effect, characterized by abnormal warming of surface waters in the equatorial Pacific Ocean. This phenomenon occurs every two to seven years, leaving warmer weather in its wake. The year 2023, already recognized as the warmest ever, commenced with El Niño, and the subsequent cycle is expected to contribute to even higher temperatures.
3. Impact of a Warming North Arabian Sea:
• The warming north Arabian Sea emerges as a significant factor behind Mumbai’s warmer temperatures. Raghu Murtugudde, a climate studies professor at IIT Mumbai, explains that global warming has prevented the dry regions over the Middle East and the Mediterranean from losing surface heat to space. This, coupled with low sea-level pressure, draws warm southwesterly winds over the Arabian Sea, rapidly warming the Northern Arabian Sea.
Expectations and Conclusion:
• While the maximum temperature is predicted to hover between 32-33 degrees Celsius for the next few days, meteorologists suggest a slight dip afterward. Sushma Nair anticipates a temperature range of 31-32 degrees for the next 2-3 days. Although a significant drop is not on the horizon, the degree of discomfort experienced by Mumbaikars may alleviate. As Mumbai navigates through this unusual January warmth, the interplay of weather patterns continues to influence the city’s climate.