Kolkata's March Rainfall Soars to Third-Highest in 15 Years
Kolkata concluded March on a notably wet note, with Tuesday's showers pushing the month's total rainfall to 55.8 mm, marking it as the third-rainiest March in the past 15 years. The city recorded an impressive 51% excess rainfall compared to the climatological average.
Significant Rainfall and Meteorological Patterns
Between Monday night and Tuesday evening, Kolkata received 8 mm of rain, contributing to the monthly tally. The Regional Meteorological Centre reported that this March saw five rainy days, four of which featured significant nor'wester spells. Climatologically, Kolkata averages 36.8 mm of rain in March with 2.1 rainy days, making this year's figures substantially higher.
HR Biswas, head at the Regional Meteorological Centre, Kolkata, explained: "Factors like frequent passing of the western disturbance and continuous moisture incursion due to anti-cyclonic flow brought frequent thunderstorm activities in March. We expect the city to remain dry in the next five days, which may lead to hot weather conditions."
Temperature Trends and Historical Context
The frequent nor'wester interventions provided relief to Kolkatans, extending the winter season and keeping temperatures moderate. The maximum temperature exceeded the normal mark on only five days, while on 26 days it remained below normal. Notably, the highest maximum temperature this month was 34.7°C on March 27, the second lowest for March in the past decade and a half.
In contrast, March 2021 saw no rainfall, with temperatures nearing 40°C by month's end. This year, however, the maximum temperature dipped below 30°C twice: 27.2°C on March 22 following 19.8 mm of rain, and 28.7°C on Tuesday, six notches below normal.
Minimum Temperature and Moisture Influence
The minimum temperature on Tuesday was 23°C, 1.6 notches below normal, but it hovered above the normal mark on 20 days due to frequent moisture incursion. It peaked at 26.3°C on Monday, highlighting the variability influenced by weather patterns.
Outlook for April and Election Precautions
Met officials anticipate April to mirror March's weather, with frequent nor'wester spells and maximum temperatures likely around or below normal. Biswas added: "The broader outlook for April is somewhat similar to what we encountered in March in terms of frequent nor'wester spells and the maximum temperature on most days likely to hover around or below the normal. While it could go up temporarily for a day or two, we expect thunderstorm activities to neutralise the rising heat at frequent intervals."
With election campaigning intensifying, the Met office has cautioned political parties to monitor IMD's nowcast alerts, issued about an hour before thunderstorms, as these spells often occur in the evenings when campaigning is active.
This weather pattern has not only impacted Kolkata but also nearly all districts in the region, which recorded excess rainfall this March, underscoring a broader meteorological trend.
