Characterizing Cold Days and Spells and Their Relationship with Cold-Related Mortality in Bangladesh

Area of Science:

• Climatology
• Meteorology
• Environmental Science

Background:

• Understanding regional temperature variations is crucial for climate adaptation.
• Cold days and spells pose risks, necessitating detailed analysis of their characteristics.

Purpose of the Study:

• To analyze the spatial and temporal characteristics of cold days and spells in Bangladesh.
• To quantify the rate of change in cold days and spells during winter months.
• To provide a method for regional-focused mitigation and adaptation strategies.

Main Methods:

• Utilized long-term daily maximum and minimum temperature data (1971-2000).
• Defined cold days based on temperature deviation from the mean and daily average air temperature.
• Quantified cold day and spell frequency and severity changes from 2000-2021.

Main Results:

• Cold days are more prevalent in northwestern regions, decreasing towards the south and southeast.
• The Rajshahi division experienced the highest number of cold spells (3.05/year), Sylhet the lowest (1.70/year).
• Extreme cold spells occurred in northwestern divisions (Rangpur, Rajshahi), while mild spells were common in southern divisions (Barishal, Chattogram).

Conclusions:

• Cold day and spell trends show a significant decrease from north to south.
• January experiences more cold spells than other winter months.
• The proposed methodology can aid in developing targeted cold-related disaster risk reduction strategies.