A large surface to volume ratio and easily accessible active reaction sites are key attributes for a good gas sensing material. Herein, we report synthesis, characterisation and humidity sensing properties of phase pure 420 nm thick low temperature (350 °C) polycrystalline V₂O₅ thin films deposited on quartz substrate by ultrasonic nebulized spray pyrolysis of aqueous combustion mixture (UNSPACM). The thin films were characterized by x-ray diffraction, Raman spectroscopy, atomic force microscope, field emission scanning microscope, transmission electron microscope, UV–visible spectroscopy and XPS. The highly porous and nanocrystalline characteristic of V₂O₅ thin films synthesized by this technique provide large surface to volume ratio and easily accessible active reaction sites making it a prominent material for gas sensing applications. The fabricated humidity sensor based on V₂O₅ thin films exhibited high sensitivity with good stability and reproducibility at room temperature. The sensor exhibited high sensitivity of 90.8% at 76% RH with response time of 35–60 s and recovery time of 7–54 s. We believe this method provides means for large-scale synthesis of V₂O₅ thin films for several gas sensing applications.