Passive daytime radiative cooling (PDRC), as a strategy to dissipate heat through an atmospheric transparency window (ATW) to outer space without any extra energy consumption, has been recently considered as a novel approach for global net-zero emissions. However, limited to expensive manufacturing, poor thermal/chemical stability, or insufficient weather-resistance, the development of a PDRC building material for long-term outdoor usages still remains a challenge. Here, a scalable superhydrophobic silica metafibers (sh-SMF) was fabricated via an electrospinning process combined with the fluorosilane-modification on fiber surface. The optically engineered sh-SMF could attain an extremely high average reflectivity (∼97 %) with near-zero absorption in the solar spectral region, due to the multiple backscattering at the fiber/air interfaces. In addition, the sh-SMF possessed a high average emissivity (∼90 %) in ATW, originated from the strong phonon resonances of the abundant Si-O bonds. Thus, the optimal sh-SMF realized a sub-ambient cooling performance of 6 °C (4 °C in nighttime) and the maximum cooling power of 112 W/m2 (87 W/m2 in nighttime) under a solar irradiance of ∼790 W/m2. Besides, the temperature decline for the sh-SMF-covered building and vehicle models could also achieve 12.7 °C and 17 °C under sunlight, respectively. Noteworthily, the ceramic sh-SMF could withstand high temperatures over 1200 °C, which might effectively prolong the time for resident to evacuate from buildings in fireground situation. Moreover, the superhydrophobic surface (contact angle=155°) of sh-SMF demonstrated attractive self-cleaning and anti-mildew properties. Furthermore, the excellent weather resistance against acid rain and ultraviolet exposure endowed the sh-SMF with long-term cooling performance. Finally, the sh-SMF with above mentioned properties opens a path for future energy-efficient and sustainable architectural applications. Display omitted •Superhydrophobic silica metafibers (sh-SMFs), fabricated through electrospinning, serving as a scalable, flexible, and flame- and weather-resistant ceramic PDRC emitter.•The optimal sh-SMFs operated with a near-zero value of Psun (<3 W/m2), and a high value of Pcooling (112 W/m2) during the daytime, resulting from high solar reflectivity (97 %) and thermal emissivity (90 %).•Maximum temperature decreases of sh-SMF–covered building and vehicle models of 12.7 and 17 °C, respectively, under sunlight.•The sh-SMFs could withstand high temperatures (>1200 °C), making them especially suitable as a building material that could effectively prolong the time available for residents to evacuate buildings in the event of fire.•The sh-SMFs display excellent self-cleaning, anti-mildew, and anti-acid abilities, combined with great UV-resistance, resulting in great weather-resistance for long-term outdoor applications.