## 4 Discussion
### Validation of LST MODIS and Landsat with MMD
El Nino conditions also shorten the monsoon season, leading to lower rainfall. Furthermore, [PERSON] et al. [50] found that the highest meteorological temperatures occurred during the peak of the 2015 El Nino, which can be attributed to the heat absorption and release properties of building materials. The average monthly temperature during normal or neutral conditions is 26 \({}^{\circ}\)C when the ONI is between \(-\)0.5 and 0.5. Based on Figure 14, it can be observed that monthly temperature changes depend on the type of ENSO event. For example, during the El Nino  
Figure 13: Direct correlation between ONI (Oceanic Niño Index) and air temperature from MMD over three months based on the ONI formula. events of 1997-1998 and 2015/2016, temperature increases were observed. The El Nino event of 1997-1998 caused a temperature change of 1.8 \({}^{\circ}\)C, while the El Nino event of 2015/2016 saw an increase of 2.5 \({}^{\circ}\)C. Overall, this study found that El Nino events caused temperature increases ranging from 0.5 \({}^{\circ}\)C to 1.5 \({}^{\circ}\)C based on RS data and data provided by the Kuching Meteorological Station. On the other hand, temperature decreases ranged from 0 \({}^{\circ}\)C to 1.2 \({}^{\circ}\)C during La Nina events. Thus, it was found that El Nino events caused temperature increases, while La Nina events caused temperature decreases in Kuching, Sarawak [4; 5]. In the context of meteorological data, it was found that Malaysia as a whole experienced a general increase in temperature of 0.38 to 0.5 \({}^{\circ}\)C [51]. Previous studies reported an average temperature increase of 0.09 to 0.34 \({}^{\circ}\)C per decade from 1971 to 2001 [52]. Similarly, [PERSON] et al. [52] found a similar increase of 0.27 to 0.40 \({}^{\circ}\)C per decade between 1961 and 2002 in Peninsula Malaysia and Northern Borneo. Comparing the findings of these studies, it was found that the urban heat island effect contributed to a 2 \({}^{\circ}\)C increase. On a global scale, [PERSON] et al. [3] confirmed that El Nino has caused temperature increases in Indochina ranging from 0.53 \({}^{\circ}\)C to 0.60 \({}^{\circ}\)C during peak El Nino periods. The study by [PERSON] et al. (2018) also found that El Nino events weakened the northeast Monsoon season. This statement was also supported by [PERSON] and [PERSON] [53], who found that El Nino events caused a general temperature increase of 0.50 to 0.65 \({}^{\circ}\)C. [PERSON] et al. [1] also stated that El Nino events led to heatwaves in Indochina, resulting in higher surface temperatures than usual. This was due to reduced rainfall in Indochina during El Nino compared to La Nina. These findings align with previous studies, such as those of [PERSON] et al. [1] and [PERSON] and [PERSON] [53]. Comparing the findings of these studies, it was found that the urban heat island effect contributed to a 2 \({}^{\circ}\)C increase. This study's findings are also similar to those of [PERSON] and [PERSON] [15], who studied the effects of El Nino on global plant systems and climate and found that the 2015/2016 El Nino event caused temperature increases ranging from 0.5 to 2.50 \({}^{\circ}\)C depending on the location. The conclusion is that the effect of ENSO events on the temperature in Kuching City, Sarawak is that El Nino events lead to an increase in temperature, while La Nina events result in a decrease in temperature. For example, during the El Nino event in  
Figure 14: The monthly mean temperature pattern changes from MMD from 1988 to 2019 in the city of Kuching. 2015/2016, there was an increase in temperature ranging from 0.5 to 1.5 \({}^{\circ}\)C. Additionally, in 2009 and 1997-1998, El Nino events also caused temperature increases of 0.5 to 1.5 \({}^{\circ}\)C. The temperature increase during El Nino is due to a decrease in rainfall in the study area, resulting in drought conditions. In 2009, the temperature increased due to a 25-30% decrease in rainfall in the Kuching City area [36].