## 3 Results
### Spatial Variability of Annual and Seasonal SUHI
#### 3.3.1 Nighttime SUHI  
The SUHI, calculated by comparing the average nighttime LST of the urban core with the minimum nighttime LST of surrounding non-urban areas, exhibits the effects of rapid urbanization. The annual nighttime SUHI effect was positive for all the cities, with the highest intensity observed in Jaipur (2.17 \({}^{\circ}\)C), followed by Lahore (1.70 \({}^{\circ}\)C), Ahmedabad (1.69 \({}^{\circ}\)C), Delhi (1.67 \({}^{\circ}\)C), Lucknow (1.50 \({}^{\circ}\)C), Faisalabad (1.49 \({}^{\circ}\)C), Hyderabad (1.47 \({}^{\circ}\)C), and Kanpur (1.43 \({}^{\circ}\)C) (Table 6). A monthly time series plot of nighttime SUHI of the different studied cities is plotted in Figure 10. The spatial variability in the seasonal characteristics of nighttime SUHI is visibly evident from Figure 10, where inland cities such as Delhi, Jaipur, Faisalabad \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline \hline
**S1.** & **City** & **Ann.** & **AMJ** & **DJF** & **Jan** & **Feb** & **Mar** & **Apr** & **May** & **Jun** & **Jul** & **Aug** & **Sep** & **Oct** & **Nov** & **Dec** \\ \hline
1. & Delhi & 1.67 & 1.87 & 1.84 & 1.60 & 2.06 & 2.51 & 2.51 & 1.88 & 1.24 & 0.66 & 0.56 & 1.17 & 1.91 & 2.05 & 1.86 \\ \hline
2. & Mumbai & 0.34 & 0.20 & 0.66 & 0.65 & 0.62 & 0.50 & 0.39 & 0.27 & \(-\)0.07 & \(-\)0.13 & \(-\)0.22 & \(-\)0.11 & 0.64 & 0.75 & 0.71 \\ \hline
3. & Dhaka & 0.53 & 0.32 & 0.94 & 0.98 & 0.98 & 0.91 & 0.55 & 0.28 & 0.12 & \(-\)0.32 & 0.03 & 0.10 & 0.37 & 0.78 & 0.85 \\ \hline
4. & Karachi & 0.60 & 0.30 & 1.29 & 1.31 & 1.32 & 1.03 & 0.74 & 0.24 & \(-\)0.08 & \(-\)0.45 & \(-\)0.50 & 0.14 & 0.95 & 1.25 & 1.24 \\ \hline
5. & Kolkata & 0.85 & 0.61 & 1.38 & 1.43 & 1.26 & 1.23 & 0.83 & 0.55 & 0.44 & 0.31 & 0.02 & 0.19 & 0.67 & 1.29 & 1.45 \\ \hline
6. & Lahore & 1.70 & 2.33 & 1.68 & 1.45 & 1.84 & 2.31 & 2.79 & 2.48 & 1.74 & 0.66 & 0.47 & 1.07 & 1.85 & 1.99 & 1.76 \\ \hline
7. & Bengaluru & 0.99 & 0.92 & 1.15 & 1.19 & 1.21 & 1.20 & 1.12 & 0.97 & 0.67 & 0.77 & 0.82 & 0.87 & 0.98 & 0.97 & 1.07 \\ \hline
8. & Chennai & 0.75 & 0.60 & 1.00 & 1.04 & 1.24 & 1.05 & 0.72 & 0.49 & 0.58 & 0.52 & 0.63 & 0.71 & 0.72 & 0.48 & 0.72 \\ \hline
9. & Hyderabad & 1.47 & 1.32 & 1.81 & 1.78 & 1.78 & 1.75 & 1.60 & 1.46 & 0.89 & 0.87 & 0.74 & 1.07 & 1.64 & 1.81 & 1.88 \\ \hline
10. & Ahmedabad & 1.69 & 1.47 & 2.56 & 2.41 & 2.81 & 3.09 & 2.50 & 1.42 & 0.49 & \(-\)1.10 & \(-\)0.38 & 0.84 & 2.40 & 2.63 & 2.47 \\ \hline
11. & Surat & 1.05 & 0.65 & 1.67 & 1.64 & 1.73 & 1.72 & 1.18 & 0.58 & 0.19 & \(-\)0.11 & 0.04 & 0.60 & 1.41 & 1.66 & 1.62 \\ \hline
12. & Pune & 1.03 & 1.01 & 1.27 & 1.28 & 1.41 & 1.37 & 1.26 & 0.99 & 0.80 & 0.66 & 0.71 & 0.78 & 0.96 & 1.06 & 1.14 \\ \hline
13. & Yangon & 0.84 & 0.33 & 1.36 & 1.29 & 1.58 & 1.35 & 0.84 & 0.58 & \(-\)0.41 & \(-\)0.49 & 1.08 & \(-\)0.37 & 0.14 & 0.82 & 1.22 \\ \hline
14. & Lucknow & 1.50 & 1.69 & 1.72 & 1.42 & 2.03 & 2.58 & 2.39 & 1.62 & 1.05 & 0.46 & 0.50 & 0.75 & 1.40 & 1.77 & 1.69 \\ \hline
15. & Faisalabad & 1.49 & 1.61 & 1.67 & 1.53 & 1.73 & 1.79 & 1.90 & 1.63 & 1.30 & 0.78 & 0.75 & 1.11 & 1.76 & 1.84 & 1.76 \\ \hline
16. & Jaipur & 2.17 & 2.17 & 2.63 & 2.49 & 2.73 & 2.93 & 2.98 & 2.13 & 1.42 & 0.79 & 0.73 & 1.52 & 2.69 & 2.88 & 2.68 \\ \hline
17. & Kanpur & 1.43 & 1.42 & 1.64 & 1.38 & 1.88 & 2.32 & 2.06 & 1.33 & 0.88 & 0.68 & 0.66 & 0.80 & 1.49 & 1.75 & 1.67 \\ \hline
18. & Dhanbad & 0.39 & 0.45 & 0.55 & 0.52 & 0.62 & 0.74 & 0.65 & 0.39 & 0.32 & 0.20 & 0.03 & 0.07 & 0.31 & 0.52 & 0.52 \\ \hline
19. & Coimbatore & 0.57 & 0.53 & 0.53 & 0.43 & 0.63 & 0.52 & 0.44 & 0.53 & 0.61 & 0.80 & 0.75 & 0.80 & 0.48 & 0.46 & 0.52 \\ \hline
20. & Colombo & 0.21 & 0.21 & 0.33 & 0.31 & 0.39 & 0.19 & 0.21 & 0.20 & 0.23 & 0.10 & 0.11 & 0.37 & \(-\)0.09 & 0.19 & 0.30 \\ \hline \hline \end{tabular} (Ann.: Annual; AMJ: April-May-June; DJF: December-January-February).  
\end{table} 
Table 5: _Cont._and Lahore observed much higher change in nighttime LST, while coastal cities such as Chennai and Mumbai observed relatively lesser change in nighttime LST.