• Inspired by human skin structure, an anisotropic synergistically performed insulation-radiation-evaporation cooler is developed by leveraging a dual-alignment structure both internal and external to the hydrogel.
• The coordinated thermal and water transport through multiscale engineering contributed to high-power synergistic passive cooling in the day and water self-regeneration at night.
• The cooler achieved an impressive cooling power of 311 W m−2 and an average sub-ambient cooling temperature of ~8.2 °C under direct sunlight.
• The synergistic design provides new insights toward high-power, sustainable, and all-weather passive cooling applications.