The climate in India

India has an extremely varied climate, influenced by the country's diverse topography and geography. The country is known for its tropical climate, characterized by hot summers, monsoon rains and cool winters. The climate in India can be broadly divided into four main regions: the northern Himalayan region, the Indo-Gangetic Plain, the southern peninsula, and the coastal regions.

The northern Himalayan region, which includes the states of Jammu and Kashmir and Himachal Pradesh, has a subarctic climate with cold winters and mild summers. During the winter months, the region receives a lot of snowfall, and the average temperature ranges from 5°C to 25°C.

The Indo-Gangetic Plain, which includes Punjab, Haryana, Uttar Pradesh, and Bihar, has a humid subtropical climate. The region experiences hot summers with temperatures reaching 40°C and cool winters with temperatures ranging from 5°C to 20°C. There is also a monsoon season here, which brings heavy rains from June to September.

The southern peninsula has a tropical humid and dry climate. The region experiences hot and humid weather throughout the year with temperatures ranging from 20°C to 40°C. The region also has two monsoon seasons: the southwest monsoon from June to September and the northeast monsoon from October to December.

The coastal regions of India have a tropical maritime climate with high humidity and frequent rainfall. Here it is hot and humid all year round with temperatures between 25°C and 35°C. The monsoon season with heavy rainfall is here from June to September.

Temperature records of the last 74 years

The hottest temperature measured from 1949 to January 2023 was reported by the Bikaner weather station. In May 2016, the record temperature of 49.5 °C was reported here. The hottest summer from July to September, based on all 49 weather stations in India below 920 meters altitude, was recorded in 1987 with an average temperature of 29.0 °C. This average temperature will normally be measured every four to six hours, thus also including the nights. Normally, this value is 28.1 degrees Celsius.

The coldest day in these 74 years was reported by the Amritsar weather station. Here the temperature dropped to -2.6 °C in January 2005. Amritsar lies at an altitude of 234 meters above sea level. The coldest winter (January to March) was in 1978 with an average temperature of 20.8 °C. In India, it is usual to have about 2.4 degrees more at 23.2 °C for this three-month period.

The most precipitation fell in July 1968. With 55.5 mm per day, the Mangalore weather station recorded the highest monthly average of the last 74 years. Incidentally, the region with the most rainfall for the whole year is around Mangaluru Airport. The driest region is near Bikaner.

Long-term development of temperatures from 1990 - 2022

In contrast to single record values, long-term development cannot simply be brought about by all weather stations in the country. Both the number and the locations are constantly changing. An average value would give a distorted result. If several measuring stations in particularly cold mountain or coastal regions are added in one year, the average would decrease as a result of this alone. If a station fails during the summer or winter months, it does not provide any values and distorts the average again. The subsequent long-term development was therefore reduced to only 4 measuring points in order to have comparable data over as long a period as possible.

In the years 1990 to 2022, there were only these 4 weather stations in the whole country, which reported continuous temperature values (Mumbai Colaba, Hyderabadort, New Delhi Safdarjungort, Machilipatnam). From these weather reports, we have created a long-term development that shows the monthly average temperatures. The hottest month in this entire period was May 1998 at 33.3 °C. January 1995 was the coldest month with an average temperature of 20.5 °C.

The average annual temperature was about 26.9 °C in the years after 1990 and about 27.4 °C in the last years before 2022. It has therefore increased only slightly by about 0.5 °C over the past 33 years. This trend only applies to the selected 4 weather stations in India. A considerably more comprehensive evaluation of global warming has been provided separately.

Data basis and methodology

The data from the individual measuring stations are based on the archives of the German Weather Service, individual values averaged and supplemented by own elements. In order to determine a representative national average, average values were first calculated for each part of the country, which were then summarized at the national level. Thus, if a disproportionate number of weather stations are located in a small area, their number does not affect the national average. There are 50 stations in India itself. In 39 cases, neighboring but nearby weather stations were also used to obtain more accurate values.