As the southwest monsoon season, running from June 1 to September 30, officially concludes, Karnataka presents a striking picture of climatic contrasts. While southern parts of the state struggled with rainfall deficits, the northern regions experienced a significant surplus, ultimately bringing the state’s overall monsoon performance to a ‘normal’ average.
Out of Karnataka’s 31 districts, only Mysuru and Chamarajanagar recorded insufficient rainfall during this period. In stark contrast, the majority of the state saw above-average rains. This uneven distribution was particularly evident in north Karnataka, where many districts that faced deficiencies in early September ended the season with an excess, as reported by the Karnataka State Natural Disaster Monitoring Centre (KSNDMC).
A Closer Look at the Cauvery Catchment
Mysuru received 324 mm of rain between June 1 and September 30, a notable 23% below its seasonal average. Similarly, Chamarajanagar district recorded 211 mm, falling 34% short of its normal levels. Even Kodagu, crucial for the Cauvery river system, received 2176 mm of rainfall this year, just 1% below its long-period average. However, according to meteorological classifications, rainfall within 19% above or below the long-period average is still considered ‘normal,’ placing Kodagu comfortably in this category.
North Karnataka’s Deluge
Conversely, numerous districts in north Karnataka witnessed abundant rainfall, leading to overflowing rivers and widespread flooding. Regions like Vijayapura, Kalaburagi, Bidar, and Yadgir experienced higher-than-normal precipitation over the four-month monsoon. Notably, Vijayapura and Kalaburagi districts received intense downpours in September. This late-season surge not only compensated for earlier shortfalls but pushed these two districts into the “large excess” category – a distinction they alone held in the state.
Vijayapura recorded 239 mm of rain in September, a remarkable 61% above its long-period average for the month. Kalaburagi followed closely with 285 mm, an impressive 63% higher than its monthly average, as per KSNDMC data. While this late heavy rainfall mitigated the overall deficiency, it also brought significant challenges, including flooding, widespread crop damage, and considerable distress to the affected communities.
Overall Performance and Reservoir Levels
Despite these regional disparities, the southwest monsoon’s overall performance in Karnataka was deemed satisfactory. No district fell into the “large deficit” category (rainfall below 60% of the long-period average). Only Mysuru and Chamarajanagar were classified as “deficient,” while 23 districts experienced “normal” rainfall, and 6 districts enjoyed “excess” rainfall, according to KSNDMC.
Further reinforcing the positive statewide outlook, major reservoirs across Karnataka are currently in a healthy state. As of September 30, 2025, the total water availability in these reservoirs stood at 827.95 tmcft, nearly reaching their gross capacity of 895.62 tmcft, indicating a robust water reserve for the coming months.