An analysis of the daily district wise rainfall data from India Meteorological Department (IMD) for the month of September 2024, the last month of India’s South West Monsoon 2024 shows that there were 546 (406 in Sept 2023[i], 417 in Sept 2022[ii] and 489 in Sept 2021[iii]) instances when district rainfall of a day was above 50 mm. Such high rainfall instances included 438 (330, 365 and 374 in Sept 2023, Sept 2022 and 2021 respectively) instances in Sept 2024 when rainfall was 50-100 mm, 73 (64, 47 and 84 in Sept 2023, Sept 2022 and 2021 respectively) instances in Sept 2024 when it was 100-150 mm, 30 (10, 3 and 20 in Sept 2023, Sept 2022 and 2021 respectively) times in Sept 2024 when it was 150-200 mm and 5 (2, 2 and 11 in Sept 2023, Sept 2022 and 2021 respectively) instances in Sept 2024 when rainfall in a day was above 200 mm.
Out of 729 districts of India, 329 districts experienced such high rainfall in Sept 2024. The highest number of such instances were seen in Uttar Pradesh, where for the 75 districts (53 of them saw such instances) there were 88 instances when rainfall was above 50 mm. W Bengal was second with 63 such instances. Interestingly, all 23 districts of W Bengal saw such instances and 22 of them saw multiple such instances.
Among the five regions of India (North, South, East, West and North East), East India had the highest number of such instances (233), followed by West India (164) and South India (73). North India had the least number of such instances in Sept 2024 at 26.
Number of High Rainfall events in Sept 2021-2024 The distribution of number of high rainfall events in various rainfall ranges (50-100 mm, 100-150 mm, 150-200 mm and above 200 mm) for Sept 2021 to 2024 can be seen in following table. The number of high rainfall events are the highest for Sept 2024 compared to previous three years for almost all the rainfall categories, even though Sept 2024 is NOT the highest compared to Sept rainfall in previous three years. This is possibly an indication to show the increasing impact of climate change on Monsoon Rainfall.
| Sept 2021 | Sept 2022 | Sept 2023 | Sept 2024 | |
| 50-100 mm | 374 | 365 | 330 | 468 |
| 100-150 mm | 84 | 47 | 64 | 73 |
| 150-200 mm | 20 | 3 | 10 | 30 |
| Over 200 mm | 11 | 2 | 2 | 5 |
| TOTAL | 489 | 417 | 406 | 546 |
| Sept All India rainfall, mm | 229.7 | 181.2 | 190.3 | 187.3 |
Regional distribution of high rainfall days in Sept rainfall during 2021-2024 In the table below we have given the regional distribution of total number of high rainfall district days in Sept 2021 to Sept 2024. Firstly, it is clear that the number of districts that experienced at least one high rainfall event in Sept 2024 at 329 is the highest in last four years. However, it is only in East India that the number of high rainfall events are highest in Sept 2024 in last four years. For North East and North, the numbers were highest in Sept 2022 and for West and South India, they were the highest in Sept 2021.
| Sept 2021 | Sept 2022 | Sept 2023 | Sept 2024 | |
| North East | 37 | 79 | 52 | 50 |
| East | 149 | 109 | 112 | 233 |
| North | 48 | 66 | 22 | 26 |
| West | 173 | 99 | 143 | 164 |
| South | 82 | 64 | 77 | 73 |
| No of districts that had such instances | 278/694 | 285/703 | 251/717 | 329/729 |
Region wise, state wise, category wise number of high rainfall instances in Sept 2024 In the following sections we are giving in tabular format, the number of high rainfall events in Sept 2024 in each state in each region, for each rainfall category. All these figures are based on IMD’s daily district wise rainfall figures during Sept 2024.
North East India In the table below are given the number of such high rainfall district days in each of the states in North East India in each of the rainfall categories in Sept 2024.
| State | No of Districts that had over 50 mm rainfall at least on one day in Sep 2024 (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 | 6 (16) | 8 | 0 | 0 | 0 | 8 |
| Assam | 6 (27) | 6 | 0 | 0 | 0 | 6 |
| Meghalaya | 4 (11) | 8 | 0 | 0 | 0 | 8 |
| Nagaland | 1 (11) | 1 | 0 | 0 | 0 | 1 |
| Manipur | 1 (9) | 1 | 0 | 0 | 0 | 1 |
| Mizoram | 2 (8) | 4 | 0 | 0 | 0 | 4 |
| Tripura | 2 (8) | 3 | 0 | 0 | 0 | 3 |
| Sikkim | 6 (6) | 16 | 3 | 0 | 0 | 19 |
| North East India | 28 (96) | 47 | 3 | 0 | 0 | 50 |
East India
| State | No of Districts that had over 50 mm rainfall at least on one day in Sep 2024 (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 200-250 mm | No of district days when Rainfall over 250 mm | Total no of district days when rainfall over 50 mm |
| W Bengal | 23 (23) | 50 | 8 | 5 | 0 | 0 | 63 |
| Odisha | 16 (30) | 23 | 0 | 1 | 0 | 0 | 24 |
| Jharkhand | 20 (24) | 30 | 4 | 0 | 0 | 0 | 34 |
| Bihar | 17 (38) | 17 | 4 | 1 | 1 | 1 | 24 |
| Uttar Pradesh | 53 (75) | 64 | 18 | 6 | 0 | 0 | 88 |
| East India | 129 (190) | 184 | 34 | 13 | 1 | 1 | 233 |
North India
| State/ Union Territory | No of Districts that had over 50 mm rainfall at least on one day in Sep 2024 (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 | 8 (13) | 10 | 4 | 1 | 0 | 15 |
| Haryana | 4 (22) | 5 | 0 | 0 | 0 | 5 |
| Chandigarh | 0 (1) | 0 | 0 | 0 | 0 | 0 |
| Delhi | 1 (9) | 1 | 0 | 0 | 0 | 1 |
| Punjab | 0 (22) | 0 | 0 | 0 | 0 | 0 |
| Himachal Pradesh | 3 (12) | 4 | 0 | 0 | 0 | 4 |
| Jammu & Kashmir | 1 (20) | 1 | 0 | 0 | 0 | 1 |
| Ladakh | 0 (2) | 0 | 0 | 0 | 0 | 0 |
| North India | 17 (101) | 21 | 4 | 1 | 0 | 26 |
West India
| State | No of Districts that had over 50 mm rainfall at least on one day in Sep 2024 (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 200-250 mm | No of district days when Rainfall over 250 mm | Total no of district days when rainfall over 50 mm |
| Rajasthan | 9 (33) | 10 | 1 | 0 | 0 | 0 | 11 |
| Madhya Pradesh | 33 (52) | 36 | 9 | 4 | 0 | 0 | 49 |
| Diu Daman, D & NH | 3 (3) | 5 | 3 | 0 | 0 | 0 | 8 |
| Gujarat | 20 (33) | 28 | 3 | 0 | 0 | 0 | 31 |
| Goa | 2 (2) | 4 | 0 | 0 | 0 | 0 | 4 |
| Maharashtra | 18 (36) | 27 | 1 | 4 | 0 | 0 | 32 |
| Chhattisgarh | 21 (33) | 20 | 6 | 3 | 0 | 0 | 29 |
| West India | 106 (192) | 130 | 23 | 11 | 0 | 0 | 164 |
South India
| State | No of Districts that had over 50 mm rainfall at least on one day in Sep 2024 (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 200-250 mm | No of district days when Rainfall over 250 mm | Total no of district days when rainfall over 50 mm |
| Andhra Pradesh | 11 (26) | 13 | 1 | 2 | 1 | 0 | 17 |
| Telangana | 31 (33) | 34 | 7 | 3 | 1 | 1 | 46 |
| Tamil Nadu | 1 (38) | 1 | 0 | 0 | 0 | 0 | 1 |
| Puducherry | 1 (4) | 2 | 0 | 0 | 0 | 0 | 2 |
| Karnataka | 4 (31) | 5 | 0 | 0 | 0 | 0 | 5 |
| Kerala | 0 (14) | 0 | 0 | 0 | 0 | 0 | 0 |
| Lakshadweep | 0 (1) | 0 | 0 | 0 | 0 | 0 | 0 |
| Andaman & Nicobar | 1 (3) | 1 | 1 | 0 | 0 | 0 | 2 |
| South India | 49 (150) | 56 | 9 | 5 | 2 | 1 | 73 |
INDIA
| Region | No of Districts that had over 50 mm rainfall at least on one day in Sept 2024 (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 | No of district days when Rainfall over 200 mm | Total no of district days when rainfall over 50 mm |
| North East | 28 (96) | 47 | 3 | 0 | 0 | 0 | 50 |
| East | 129 (190) | 184 | 34 | 13 | 1 | 1 | 233 |
| North | 17 (101) | 21 | 4 | 1 | 0 | 0 | 26 |
| West | 106 (192) | 130 | 23 | 11 | 0 | 0 | 164 |
| South | 49 (150) | 56 | 9 | 5 | 2 | 1 | 73 |
| INDIA | 329 (729) | 438 | 73 | 30 | 3 | 2 | 546 |
Note: The figures in the bracket in the last two for columns 3-7 are for previous year. Figures in the bracket in second row are the number of total districts in specific state or region in all the tables.
One can see in above table that the total no of high rainfall district days during Sept 2024 were 546 (406 in Sept 2023, 417 in Sept 2022, 489 in Sept 2021), highest in last four years.
SANDRP (ht.sandrp@gmail.com)
[i] https://sandrp.in/2023/11/01/high-rainfall-days-in-indias-districts-in-sept-2023/
[ii] https://sandrp.in/2022/10/02/high-rainfall-days-in-indias-districts-in-sept-2022/
[iii] https://sandrp.in/2021/10/07/high-rainfall-days-in-indias-districts-in-sept-2021/
SANDRP 