As extreme heat intensifies across the United States, it is often assumed that rising temperatures will drive people to relocate. However, new research from Florida Atlantic University challenges that expectation, suggesting that heat alone is not yet prompting large-scale population departures. Instead, the study indicates that while higher temperatures may reduce the appeal of certain regions to prospective newcomers, they are not causing widespread out-migration. The findings point to a more nuanced reality in which climate plays a role, but not the dominant one many anticipate.

Drawing on county-level data across the contiguous United States, including IRS migration records from 2020 to 2022, U.S. Census data, and climate indicators from National Oceanic and Atmospheric Administration and the Centers for Disease Control and Prevention, researchers examined how temperature changes influence migration patterns. Their analysis reveals that rising heat is more likely to slow population growth in certain areas by discouraging in-migration rather than forcing residents to leave. In other words, places are becoming less attractive rather than actively pushing people out.

The study, published in Sustainability, finds that economic opportunity, housing affordability, and overall quality of life remain the primary drivers of where people choose to live. Counties with strong labour markets, lower housing costs, and desirable amenities continue to attract residents despite increasing temperatures. Meanwhile, population decline in other regions appears more closely tied to longstanding economic and demographic trends than to climate conditions alone. Many counties still experience net population gains, particularly in rapidly growing Sun Belt regions such as Florida, Texas, and Arizona, even as these areas face some of the most pronounced temperature increases.

An important dimension highlighted by the research is the concept of immobility. Rather than relocating in response to gradual climate stress, many individuals remain in place, either by adapting to changing conditions or because financial and structural barriers limit their ability to move. This raises concerns about the emergence of “trapped populations,” particularly in lower-income communities where resources to respond to environmental change are more constrained. In these contexts, vulnerability to heat may intensify without corresponding shifts in population.

The temperature change itself is uneven across the country. On average, U.S. counties experienced an increase of approximately 1.9°F between 2017 and 2021 compared with a 1901–2000 baseline, though local variation ranges from slight cooling to increases exceeding 3.7°F. Hundreds of counties have already experienced warming above 2.6°F, with some surpassing 3°F. The most significant increases are concentrated in parts of the Southwest, Southeast, and Northeast, as well as specific counties in Colorado and Ohio. Despite these variations, migration patterns remain relatively stable at lower to moderate levels of warming, with only modest shifts emerging at higher temperature thresholds.

The researchers caution that current trends do not preclude stronger climate-driven migration in the future. As rising temperatures interact with extreme weather events, prolonged exposure, housing constraints, and insurance pressures, more pronounced population shifts could emerge. The findings suggest that policymakers should prioritise strengthening resilience in place rather than preparing for immediate large-scale migration. Investments in heat-resilient housing, infrastructure, and support for vulnerable populations will be critical, as the interplay between climate, economic conditions, and social inequality continues to shape how and where people live.

More information: Yanmei Li et al, Temperature Anomaly and Residential Mobility: Spatial Patterns, Tipping Points, and Implications for Sustainable Adaptation, Sustainability. DOI: 10.3390/su18042040

Journal information: Sustainability Provided by Florida Atlantic University