## 4 Discussion
The figure clearly displays the influence of geographical location and its related climatic conditions over the seasonal SUHI intensity, though the extent of variability might depend on other factors. Studies on the effect of vegetation cover  
Figure 13: Bar chart showing seasonal (**a**) nighttime and (**b**) daytime SUHI effect over major Indian and other cities for AMJ (April–May–June) and DJF (December–January–February) for the period 2000–2023. over India reveal much less pre-monsoon vegetation cover on the IG plains. During the pre-monsoon summer season, barren rural land has lower albedo compared with built-up regions resulting in high LST, while the same is not true for nighttime as albedo is absent during nighttime [89; 103]. Jaipur and Lahore are inland cities, whereas Dhaka and Colombo are near-coastal to coastal cities. The influence of their geographical locations is visible in their total change in annual LST over 23 years and the monthly breakdown of nighttime SUHI. The total change in annual LST over the study period for Colombo and Dhaka was 0.83 and 0.09 \({}^{\circ}\)C, while for Jaipur and Lahore was 1.35 and 1.68 \({}^{\circ}\)C, respectively. Jaipur and Lahore had highly positive nighttime SUHI during the AMJ and DJF months. Jaipur showed a SUHI of 2.17 \({}^{\circ}\)C during AMJ and 2.63 during DJF, while Lahore showed a SUHI of 2.33 \({}^{\circ}\)C during AMJ and 1.68 during DJF which significantly weakened during monsoon months (June-July-August). A difference of approximately 2 \({}^{\circ}\)C in SUHI was observed between April and August in both cities (Figure 10c and Table 6). This can be seen as a general trend in inland cities. Coastal cities, however, do not show much difference in SUHI patterns over months or seasons. The monthly and seasonal breakup of SUHI for Dhaka and Colombo showed relatively no significant highs or lows. Both cities showed a SUHI effect below 1 \({}^{\circ}\)C. Colombo, being very close the coast compared with Dhaka, showed a much more uniform SUHI effect (in the range of 0.1 to 0.39 \({}^{\circ}\)C) throughout the months (Table 6). Ahmedabad and Delhi were among the leading five cities exhibiting the most significant annual nighttime SUHI effect. Delhi, being the most populous and extensively urbanized city in India, gauges its level of urbanization through a substantial increase in population, with a decadal urbanization rate of 26.8% from 2001 to 2011. Projections indicate that Delhi is poised to surpass Tokyo as the world's most populated city [104]. Ahmedabad, characterized as an industrial hub, ranks as the seventh-largest metropolitn city in India, accommodating a population of 7.68 million. The influence of urbanization is evident from the strong positive nighttime SUHI observed in both cities annually and seasonally (AM) and DJF). The total change in nighttime LST over 23 years based on linear fit (Table 1) showed a strong positive annual change and a total change of 3.70 \({}^{\circ}\)C and 3.01 \({}^{\circ}\)C for Ahmedabad and Delhi during MJJ months. Notably, June-July marks the monsoon months during which cities in the country receive substantial rainfall, accompanied by monsoon winds and abundant greenery which collectively help alleviate the formation of SUHI. In contrast with this, the monthly nighttime SUHI presented in Table 6 shows strong positive SUHI even in May, June, and July for both Delhi and Ahmedabad, except with Ahmedabad showing an urban cool island effect only in July, supported by earlier studies [105]. The implications of UHI will be stronger in summers with higher summer temperatures increasing air conditioning and energy demand, further increasing atmospheric pollution. The life quality of low-income families in these cities will deteriorate further given the close connection between the indoor thermal environment and outdoor conditions. The increasing SUHI effect in urban areas leads to heightened heat stress and raises significant concerns.