Quantifying Urban Heat Island Effects Using Satellite Thermal Imagery: A Multi-City Analysis

Abstract: This study presents a comparative analysis of urban heat island (UHI) intensity across twelve metropolitan areas using Landsat 8 thermal infrared imagery. Our findings demonstrate a strong correlation between impervious surface coverage and nocturnal temperature differentials, with implications for urban planning and climate adaptation strategies.

Introduction

Urban heat islands—the phenomenon where cities experience significantly higher temperatures than surrounding rural areas—represent one of the most well-documented impacts of urbanization on local climate. While the existence of UHI effects has been recognized since the 1820s, the ability to quantify and map these thermal patterns at high resolution has only become practical with advances in satellite remote sensing.

Methodology

We analyzed 847 cloud-free Landsat 8 scenes acquired between 2020-2025 covering twelve U.S. metropolitan areas ranging in population from 500,000 to 8 million. Land surface temperature (LST) was derived from thermal infrared bands using the split-window algorithm, with atmospheric correction applied using MODTRAN radiative transfer modeling.

Study Areas

Cities were selected to represent diverse climate zones, urban morphologies, and development patterns: Phoenix, Houston, Atlanta, Chicago, Boston, Seattle, Denver, Miami, Minneapolis, Portland, Sacramento, and Baltimore.

Key Findings

Our analysis revealed several significant patterns:

1. Mean UHI intensity ranged from 2.3°C (Seattle) to 7.8°C (Phoenix)
2. Impervious surface fraction explained 73% of variance in daytime LST (R² = 0.73, p < 0.001)
3. Cities with extensive urban tree canopy showed 1.5-2.1°C lower peak temperatures
4. Nocturnal UHI intensity exceeded daytime values in 9 of 12 cities

Discussion

These findings support the growing body of evidence linking urban form to thermal comfort and energy consumption. The strong predictive relationship between impervious surfaces and temperature suggests that relatively simple remote sensing metrics could support UHI mitigation planning without requiring extensive ground-based monitoring networks.

Conclusion

Satellite thermal remote sensing provides a cost-effective approach for characterizing urban thermal environments at policy-relevant scales. Future work should examine the relationship between UHI patterns and health outcomes, particularly during extreme heat events.

Full methodology and supplementary data available at doi:10.xxxx/bwgeo.2026.uhi