Extremely moist conditions permeate India during May 2023, exceeding precipitation records from 1901 with 126.7mm of rainfall, according to the India Meteorological Department report.
Floodin' Season: India Records Wettest May in over a Century due to Early Monsoon
☔️ Delhi, India: India experienced a drenched May, with an average rainfall of 126.7mm last month, as per the India Meteorological Department (IMD), marking the wettest May since 1901.
🌦️ The heavy rainfall was primarily due to the early onset of the southwest monsoon, which brought relentless showers across southern and eastern parts of the country.
📝 In a recent post on its platform, the IMD noted, "The average monthly rainfall for May 2025 over All-India (126.7 mm) and Central India (100.9 mm) was the highest since 1901."
Further Reading:
- Video: India's monsoon drenches Mumbai as it arrives early
- India's early monsoon boosts crop outlook, raises hopes for export easing
Regionally, South Peninsular India received 199.7 mm of rainfall last month, the second-highest since 1901, followed only by 201.4 mm in 1990. Northwest India recorded 48.1 mm, the 13th highest since 1901 and the 4th highest since 2001. East and Northeast India saw 242.8 mm of rainfall, the 29th highest since 1901 and the 4th highest since 2001.
According to the IMD, May 2025 saw:- 25 meteorological subdivisions with large excess rainfall,- Five with excess rainfall, and- Six with normal rainfall.
Extremely heavy rainfall was reported along the West Coast, as well as in Assam and Meghalaya, Sub-Himalayan West Bengal and Sikkim, Mizoram, Tamil Nadu, Puducherry and Karaikal, Madhya Maharashtra, and South Interior Karnataka.
Very heavy rainfall occurred in regions including Arunachal Pradesh, Bihar, Coastal Andhra Pradesh and Yanam, East Rajasthan, Haryana, Chandigarh and Delhi, Marathwada, North Interior Karnataka, Rayalaseema, Saurashtra and Kutch, Telangana, Vidarbha and West Madhya Pradesh.
The IMD also recorded seven Western Disturbances (WDs) during May, triggering frequent thunderstorms, gusty winds, and hailstorms across the Western Himalayan region and the plains of northwest and central India. These unseasonal weather activities helped keep temperatures in check.
Historically, the Southwest Monsoon in India has shown significant variability, with an average arrival date over Kerala around June 1, initiating the four-month rainy season that contributes over 70% of India's annual rainfall[5]. Nevertheless, the past 20 years have witnessed an increasing trend of early arrivals, with the monsoon coming ahead of schedule more than half the time[1].
Years such as 2009 and 2025 stand out as the monsoon arrived on May 23 and May 24, respectively, marking the earliest onset since 2009[1][3][5]. The early onset of the Southwest Monsoon is attributed to a mix of favorable atmospheric and oceanic factors, including the presence of increased cloudiness and atmospheric convection (low Outgoing Longwave Radiation levels), warm ocean temperatures, and the formation of specific weather systems in the Arabian Sea and the Bay of Bengal[4].
Although an early onset does not guarantee an increase in total seasonal rainfall, it can affect the intensity of the rains during June and impact agricultural activities by potentially damaging crops or advancing sowing dates for kharif crops[1].
- In the light of the early onset of the monsoon, the India Meteorological Department (IMD) has shared a post on its platform, mentioning the news of the unusual weather event and the weather reports showing the second-highest rainfall in South Peninsular India since 1901.
- The heavy rainfall in May 2025, accompanied by thunderstorms and hailstorms, has highlighted the importance of environmental-science research in understanding the impact of these weather conditions on the overall climate and agricultural activities in India.
