Cities and urbanization can accelerate climate change. Every urban functioning depends on energy, consuming fossil fuels for various purposes and releasing anthropogenic carbon dioxide (CO2). Clearing land for cities and modifying natural land cover to build and run cities increase urban heat capacity and make the city environment thermally not bearable by the city dwellers. Therefore, existing cities should be turned to adapt, and new city planning should be built for resilience towards the impact of climate change. This study was planned with the overarching objective of exploring the current situation of vulnerability and resilience of Muscat City, the capital of the Sultanate of Oman. The aspects of vulnerability, namely exposure, sensitivity, and adaptive capacity based on the framework of IPCC, are targeted with specific objectives through multidisciplinary investigation. The exposure component in this study was aimed to assess the phenomenon of UHI in Muscat city. This was carried out with an extensive primary investigation through field measurements in parallel with meteorological and remotely sensed data from 2019- 2020. Land surface and air temperatures were measured using a non-contact infrared and used as input to calculate UHI. A total of 8352 measurements of land surface and air temperature were collected to investigate UHI during day and night, winter and summer season covering different land uses and land cover (Residential, Commercial, Residential/Commercial, Greenery space, and Industrial) and in different land cover (Road, Pavement, Bare soil, Vegetation) across the sub-cities with rural reference of Izki in Al-Dakhiliya governorate. This investigation was accomplished by statistically analyzing the relationship between the variables and how the variables influence the UHI effect in the local environment. The finding of the in-situ measurement shows UHI varied from 0.24 to 6.74 °C across all sub-cities based on land surface temperature. In contrast, air temperature measurements indicate the formation of UHI in some sub-cities with maximum values of 4.65 °C in Bowshar and 4.17 °C in Al Amrat at the night and the absence of this phenomenon in others. Overall, the strength of UHI is higher in the winter season. Analyzing meteorological and remotely sensed data highlights findings from field measurements, with the formation of UHI in all sub-cities in winter with values ranging from 0.43-5.37 °C and its absence in most sub cities during the summer. There are significant differences (p ≤ 0.05) among the land use types, with greenery space having the lowest mean value (21.70 ± 0.59 °C). The fact that the mean temperature of the land's surface, in regard to the type of land cover, follows the pattern of road > pavement > bare soil > vegetation, with the exception of the daylight in the summer, indicates very clearly the role of vegetation in lowering the UHI effect. This was also confirmed by the findings that the air temperature above the vegetation cover was reduced by 1.3 °C to 2.1 °C during the daytime and by 2.6 °C to 3.1 °C during the nighttime. In addition, there was a moderate correlation (R2= 0.58) between the temperature of the land surface and the air during the winter, in contrast to the summer (R2 = 0.29), when the association was weaker. Quantification of the urban heat island effect (UHI) is essential for city planners in pursuit of sustainable urbanization, taking into account changes in land use and land cover in the future and building resilient cities. The adaptive capacity component was aimed by estimating the carbon storage and sequestration potential of the vegetation in the selected vegetation in Muscat city. Estimation of the parameters was done through using existing allometric models. Field works involved measuring the circumference of tree as biophysical parameters. A total of 3864 trunks in 2860 trees, belonging to 36 species, were measured at the sampling area. The investigation was performed between December 2020 and March 2021, by using a stratified sampling method. Parks and roadside plantations were chosen, and plot/transect technique was utilized. In addition, Normalized difference vegetation index (NDVI) derived from satellite data was obtained and correlated with the finding from the field. The outcome of this objective found that there is a significant difference (P ≤ 0.05), in terms of carbon storage amongst the sub-cities. Carbon storage ranges between 88.1 tonne C to 1192.0 tonne C. In general, the pattern of sub-cities regarding to carbon storage and carbon sequestration is A'seeb > Muttrah > Bowshar > Muscat > Al Amrat. On average, each tree in the parks absorbs 3.2 ± 0.1 tonnes of carbon dioxide equivalent (CO2eq), bringing the total quantity of carbon dioxide removed from the atmosphere by the trees to around 5227.6 tonnes. By contrast, a roadside plantation may absorb 5985.7 tonne of carbon dioxide, or 4.9 ± 0.2 tonne per tree. The contribution of different species in this total amount of carbon sequestered differs from one species to others. It found that Ficus spp. providing the highest contribution to carbon sequestration (CO2eq), at 30.3%, with a total of 3399.3 tCO2eq, followed by Azadirachta indica (25.4%), at 2845.2 tCO2eq, and Conocarpus erectus (20.4%), at 2286 tCO2eq. Overall, the findings indicate that carbon-storing vegetation is critical for the maintenance of a sustainable environment in the city. Plantation projects on both existing and new land uses, as well as along the roadside, were found to have the potential to boost carbon sequestration in urban areas. The impact of outdoor microclimate on the thermal comfort of Muscat inhabitants was assessed in the summer season. A total of 415 face-to-face questionnaires were collected using a transversal field survey. The thermal sensation was ranked according to ASHRAE 7-point scale and thermal and other environmental parameters preference was ranked using the Mclntyre scale. Objective and subjective parameters were collected simultaneously via Kestrel 5400 Heat Stress Tracker and structured questionnaire respectively. Then, RayMan Pro version 3.1 software was used to compute Physiological Equivalent Temperature (PET) values. The physiological Equivalent Temperature (PET) range for Omani inhabitants was obtained of 23.6 °C 30.8 °C and neutral PET of 27.2 °C. Physiological Equivalent temperature (PET) had a moderate correlation (R= 0.7, R2= 0.50) with thermal sensation votes and it is significant at the 0.01 level (2-tailed). A linear regression model specific to the country's climatic zone and the national dress code of the citizens was established as: TSV= (0.14 ×PET)-3.8. Finally, the objective of general vulnerability assessment was carried out by identifying multiple indicators from the primary findings and also from available secondary data covering three components exposure, sensitivity and adaptive capacity. Two frameworks were used, namely the Intergovernmental Panel on Climate Change (IPCC) methods and the Sendai framework of the United Nations of Disaster Risk Reduction (UNDRR). The findings revealed the A'seeb sub-city (Wilayate) has a lower vulnerability index value of -1.260 due to the high resilience index scoring a value of 1.000. While Al Amrat and Muscat sub-cities are with high vulnerability values of -0.010 and 0.440, respectively. The larger outcome of this objective may provide future studies with this initial set of indicators and also assist Ministries and Authorities in expanding such assessment to other rapidly emerging cities across the Sultanate of Oman. It may be helpful to summarize these findings from a wide range of perspectives and use them as a starting point for future studies to identify vulnerability and building resilience in Muscat city. These findings could be helpful for decision-makers as they implement the country's National Urban Development Strategy (NUDS) and Oman's 2040 vision.