Bhubaneswar: A prolonged heat wave spell of five days or more will simply be unbearable for the people under Sun.
But the big breaking hotter fact has been that during the last five years, Odisha has ranked high among the States in India that have experienced prolonged heatwaves, particularly for five consecutive days or more.
As per IMD report, during the last two years, heatwave events in Odisha had been mainly observed in June 2023, and April-May-June months of 2024. This shows March has not witnessed major heat wave days in year 2023 and 2024.
However, as per the Summer Outlook 2025 released by IMD, Odisha is going to record more heat wave days (around 44) during the 3-month period of March-April-May.
The IMD outlook mentions about March 2025 recording above normal maximum temperatures in Odisha.
LONGER HEAT WAVE STRIKES WHICH DISTRICTS IN ODISHA?
An IMD study shows over the long period of 1961 – 2020, following districts in Odisha have recorded a rise in heat wave days. Below is the image that shows how heat wave days had been increased over in the years.
- Angul
- Bargarh
- Balangir
- Bhubaneswar
- Bhadrak
- Boudh
- Cuttack
- Dhenkanal
- Debgrah
- Jharsuguda
- Jagatsinghpur
- Jajpur
- Khordha
- Kendrapada
- Parts of Nayagarh
- Sambalpur
- Sundergarh
- Sonepur
WHAT ARE WEATHER REASONS BEHIND HEAT WAVE DAYS RISE?
Here are the reasons, the national weather forecaster, IMD, has reasoned for the longer heat wave days experienced in Odisha. It lists out the following.
- Presence of persistent anticyclonic circulation over the State
- This results in pulling with dry North-Northwesterly/Westerly winds
- Which leads to heat advection (heat transfer) over the area.
WHY COASTAL REGIONS UNDER FIRE?
The IMD study has attributed the following reasons behind the increasing heat wave day spell in the coastal regions of the State. It has reasoned the following weather developments over Odisha during summer.
- Delayed setting up of sea breeze over coastal regions due to prevailing dry low-level Northwesterly/Westerly winds.
- Besides delayed setting, sea breeze over coastal area weakens.
- The weakening of sea breeze is attributed to the impact of westerly warmer continental winds
EL NINO, LA NINA YEARS EQUALLY VENGEANT
The IMD study points out that coastal Odisha bears the brunt of heat wave days be it El Nino or La Nina years. (view the image below).
As per NOAA ENSO forecast, Summer 2025 will be witnessing neutral ENSO (El Nino Southern Oscillation) conditions. Still, the heat wave days will higher and maximum temperature will be above normal in the State.
VEHICULAR EMISSION BEHIND HEAT WAVES?
The IMD study found that Greenhouse gas emissions from fossil fuels are likely the cause of this observed trend in heat waves over the years.
GHGs are known as heat trappers. Therefore, the intensity of heat wave has risen over the years.
