Uranus, with its extreme axial tilt and enigmatic energy balance, presents a particularly compelling case. In this study, we present the global-average radiant energy budget spanning a complete orbital period (1946–2030) based on observations and modeling, revealing significant seasonal variations driven primarily by Uranus’ highly variable solar flux.

Despite these fluctuations, our results show that emitted thermal power consistently exceeds absorbed solar power, indicating a net energy loss. From these seasonal variations, we determine a statistically significant internal heat flux, resolving the long-standing debate on its magnitude. Furthermore, we analyze the energy budget of Uranus’ weather layer by integrating internal heat with radiant energies, uncovering substantial energy imbalances at both global and hemispheric scales.

This is the first study to quantify seasonal energy imbalances on Uranus. Our findings provide critical insights into the planet’s thermal dynamics for future investigations, including those by a potential flagship mission to Uranus.