An analysis of the daily district wise rainfall data from India Meteorological Department (IMD) for the month of June 2023, the first month of India’s South West Monsoon 2022 shows that there were instances (462 in June 2022[i] and 442 in June 2021) when district rainfall of a day was above 50 mm. This is high considering that the rainfall of India in June 2023 was 148.6 mm[ii], the rainfall of India in June 2022 was 152.3 mm[iii], or daily average rainfall is about 5 mm. The high rainfall instances in June 2023 included 339 (339 and 371 in June 2022 and 2021) instances when rainfall was 50-100 mm, 68 instances (68 and 59 in June 2022 & 2021) when it was 100-150 mm, 26 (26 and 5 times in June 2022 & 2021) times it was 150-200 mm and 29 (29 & 7 times in June 2022 & 2021) times above 200 mm.
Climate Change footprint on Rainfall pattern in June 2022 When we compare these figures with the figures of high rainfall district days in June 2021[iv] (when rainfall was 182.9 mm, over 30 mm more than the rainfall in June 2022), we see that the total number of such days is higher in 2022 as also the district days when day rainfall is 100-150 mm, day rainfall is 150-200 mm and when day rainfall is over 200 mm, even when June 2022 rainfall is lower than the rain in June 2021. This is a clear indication of rainfall pattern getting more skewed towards high intensity rainfall days interspersed with drier periods. This is clearly footprint of climate change on rainfall pattern.
High Rainfall district days in June 2022 Out of 703 districts of India, 154 districts or about a third of the districts experienced high rainfall days in June 2022. There were some districts that had more than one such high rainfall days in June 2022. The highest number of such instances were seen in Assam, Meghalaya and Arunachal Pradesh of North East India, where for the 54 districts that belong to these three states, there were 254 instances when rainfall was above 50 mm. .
Among the five regions of India (North, South, East, West and North East), North East India had the highest number of such instances (304), followed by East India (65). North India had by far the least such instances at 20, the monsoon had not yet arrived in most states of North by the end of June 2022.
North East India
| State | Districts that had over 50 mm rainfall at least on one day in June 2023 (Total no of districts) | No of district days when rainfall 50-100 mm | No of district days when Rainfall 100-150 mm | No of district days when Rainfall 150-200 | No of district days when Rainfall over 200 mm | Total no of district days when rainfall over 50 mm |
| Arunachal Pradesh | 9 (16) | 23 | 0 | 0 | 0 | 23 |
| Assam | 18 (27) | 58 | 13 | 1 | 0 | 72 |
| Meghalaya | 9 (11) | 33 | 11 | 6 | 4 | 54 |
| Nagaland | 3 (11) | 3 | 0 | 0 | 0 | 3 |
| Manipur | 4 (9) | 7 | 0 | 0 | 0 | 7 |
| Mizoram | 5 (8) | 5 | 0 | 0 | 0 | 5 |
| Tripura | 6 (8) | 10 | 0 | 0 | 0 | 10 |
| Sikkim | 4 (4) | 13 | 0 | 0 | 0 | 13 |
| North East India | 58 (94) | 152 | 24 | 7 | 4 | 187 |
East India
| State | Districts that had over 50 mm rainfall at least on one day in June 2023 (Total no of districts) | No of district days when rainfall 50-100 mm | No of district days when Rainfall 100-150 mm | No of district days when Rainfall 150-200 | No of district days when Rainfall over 200 mm | Total no of district days when rainfall over 50 mm |
| W Bengal | 7 (19) | 23 | 5 | 0 | 0 | 28 |
| Odisha | 12 (30) | 15 | 2 | 0 | 0 | 17 |
| Jharkhand | 3 (24) | 3 | 0 | 0 | 0 | 3 |
| Bihar | 12 (38) | 12 | 0 | 0 | 0 | 12 |
| Uttar Pradesh | 15 (75) | 12 | 3 | 0 | 0 | 15 |
| East India | 49 (186) | 65 | 10 | 0 | 0 | 75 |
North India
| State/ Union Territory | Districts that had over 50 mm rainfall at least on one day in June 2023 (Total no of districts) | No of district days when rainfall 50-100 mm | No of district days when Rainfall 100-150 mm | No of district days when Rainfall 150-200 | No of district days when Rainfall over 200 mm | Total no of district days when rainfall over 50 mm |
| Uttarakhand | 4 (13) | 6 | 0 | 0 | 0 | 6 |
| Haryana | 3 (22) | 3 | 0 | 0 | 0 | 3 |
| Chandigarh | 0 (1) | 0 | 0 | 0 | 0 | 0 |
| Delhi | 2 (9) | 2 | 0 | 0 | 0 | 2 |
| Punjab | 1 (22) | 2 | 0 | 0 | 0 | 2 |
| Himachal Pradesh | 3 (12) | 4 | 0 | 0 | 0 | 4 |
| Jammu & Kashmir | 3 (20) | 2 | 1 | 0 | 0 | 3 |
| Ladakh | 0 (2) | 0 | 0 | 0 | 0 | 0 |
| North India | 16 (101) | 19 | 1 | 0 | 0 | 20 |
West India
| State | Districts that had over 50 mm rainfall at least on one day in June 2023 (Total no of districts) | No of district days when rainfall 50-100 mm | No of district days when Rainfall 100-150 mm | No of district days when Rainfall 150-200 | No of district days when Rainfall over 200 mm | Total no of district days when rainfall over 50 mm |
| Rajasthan | 12 (33) | 8 | 1 | 5 | 2 | 16 |
| Madhya Pradesh | 24 (52) | 30 | 2 | 1 | 0 | 33 |
| Diu Daman | 2 (2) | 3 | 1 | 0 | 0 | 4 |
| Gujarat | 18 (33) | 28 | 9 | 1 | 0 | 38 |
| Dadra Nagarhaveli | 1 (1) | 4 | 1 | 0 | 0 | 5 |
| Goa | 2 (2) | 7 | 3 | 0 | 0 | 10 |
| Maharashtra | 10 (36) | 25 | 6 | 1 | 0 | 32 |
| Chhattisgarh | 12 (27) | 16 | 1 | 1 | 0 | 18 |
| West India | 81 (186) | 121 | 24 | 9 | 2 | 156 |
South India
| State | Districts that had over 50 mm rainfall at least on one day in June 2023 (Total no of districts) | No of district days when rainfall 50-100 mm | No of district days when Rainfall 100-150 mm | No of district days when Rainfall 150-200 | No of district days when Rainfall over 200 mm | Total no of district days when rainfall over 50 mm |
| Andhra Pradesh | 1 (26) | 1 | 0 | 0 | 0 | 1 |
| Telangana | 0 (33) | 0 | 0 | 0 | 0 | 0 |
| Tamil Nadu | 2 (38) | 3 | 0 | 0 | 0 | 3 |
| Puducherry | 0 (4) | 0 | 0 | 0 | 0 | 0 |
| Karnataka | 3 (30) | 5 | 0 | 0 | 0 | 5 |
| Kerala | 2 (14) | 2 | 0 | 0 | 0 | 2 |
| Lakshadweep | 0 (1) | 0 | 0 | 0 | 0 | 0 |
| Andaman & Nicobar | 2 (3) | 2 | 0 | 0 | 0 | 2 |
| South India | 10 (149) | 13 | 0 | 0 | 0 | 13 |
INDIA
| Region | No of Districts that had over 50 mm rainfall at least on one day in June 2023 (Total no of districts) | No of district days when rainfall 50-100 mm | No of district days when Rainfall 100-150 mm | No of district days when Rainfall 150-200 | No of district days when Rainfall over 200 mm | Total no of district days when rainfall over 50 mm |
| North East | 58 /94 | 152 (195) | 24 | 7 | 4 | 187 (304) |
| East | 49 /186 | 65 (54) | 10 | 0 | 0 | 75 (65) |
| North | 16 /101 | 19 (19) | 1 | 0 | 0 | 20 (20) |
| West | 81 /186 | 121 (35) | 24 | 9 | 2 | 156 (36) |
| South | 10 /136 | 13 (36) | 0 | 0 | 0 | 13 (37) |
| INDIA | 214 /716 | 370 (339) | 59 (68) | 16 (26) | 5 (29) | 451 (462) |
In the table above, the figures given in the brackets are for the month of June 2022 for the respective parameters. We can see the very high number of high rainfall district days occurring in West India in June 2023 compared to those in June 2022. This is largely due to cyclone Biparjoy. We can also see that for the rest of the regions, the numbers in June 2023 are in the same range as those in June 2022, though somewhat lower as in case of South and NE India. We can also see that the number of district days for rainfall in a day of 100-150 mm, 150-200 mm and above 200 mm are each lower in June 2023 compared to those in June 2022, as national rainfall in June 2023 was lower than that in June 2022.
| Month | Rainfall in the month in mm | No of districts that had at least one day with rainfall over 50 mm/ Total no of districts | No of district days when rainfall 50-100 mm | No of district days when rainfall 100-150 mm | No of district days when rainfall 150-200 mm | No of district days when rainfall over 200 mm | No of district days when rainfall over 50 mm |
| June 2021 | 182.9 | 219/ 694 | 371 | 59 | 5 | 7 | 442 |
| June 2022 | 152.3 | 154/ 703 | 339 | 68 | 26 | 29 | 462 |
| June 2023 | 148.6 | 214/ 716 | 370 | 59 | 16 | 6 | 451 |
In the table above, the number of district days with high rainfall of various range is given for June 2021, 2022 and 2023, along with total number of such instances and total number of districts affected. We can see that in June 2023, total rainfall (148.6 mm) was much lower than that in June 2021 (182.9 mm), but the number of high rainfall districts in June 2023 (214) is almost same as in June 2021 (219) and frequency of high rainfall district days have increased from 442 in June 2021 to 451 in June 2023. This is an indication of the rainfall getting increasingly skewed in favour of high intensity rainfall.
SANDRP (ht.sandrp@gmail.com)
END NOTES:
[i] https://sandrp.in/2022/07/14/june-2022-high-rainfall-district-days-in-indias-sw-monsoon/
[ii] https://sandrp.in/2023/07/07/june-2023-district-wise-rainfall-in-indias-sw-monsoon/
[iii] https://sandrp.in/2022/06/30/june-2022-district-wise-rainfall-in-in-indias-sw-monsoon/
[iv] https://sandrp.in/2021/07/23/high-rainfall-days-in-indias-districts-in-june-2021/
SANDRP 