A method for estimating a road surface condition, comprising the steps of: (a) dividing a time-series waveform of tire vibrations in a circumferential direction or in an axial direction during vehicular travel detected by an acceleration sensor installed within the tire into a pre-leading-edge region R1, which precedes a leading-edge peak appearing at the leading edge of contact patch, a leading-edge region R2, which is the region constituting the leading-edge peak, a pre-trailing-edge region R3, which falls between the leading-edge peak and a trailing-edge peak appearing at the trailing edge, a trailing-edge region R4, which is the region constituting the trailing-edge peak, and a post-trailing-edge region R5, which follows the trailing-edge peak; (b) obtaining from the time-series waveform: a band value P 11 selected from a band of 2 kHz to 8 kHz of the pre-leading-edge region R1, a band value P 12 selected from a band of 0.5 kHz to 1.5 kHz of the pre-leading-edge region R1, a band value P 21 selected from a band of 1 kHz to 3 kHz of the leading-edge region R2, and a band value P 51 selected from a band of 1 kHz to 4 kHz of the post-trailing-edge region R5; and (c) estimating whether the road surface during vehicular travel is a snowy road or not, based on the magnitude of the band values P 11, P 12, P 21, and P 51, wherein, in the step (c), the road surface during vehicular travel is estimated to be a snowy road when f1 ≥ 0 and also f2 < 0, where f1 is a function value found by substituting the band values P 11 and P 12 in a predetermined discriminant function F1 = w 11 · P 11 + w 12 · P 12 - K1 and f2 is a function value found by substituting the band values P 21 and P 51 in a predetermined discriminant function F2 = w 21 · P 21 + w 22 · P 51 - K2. (a) dividing a time-series waveform of tire vibrations in a circumferential direction or in an axial direction during vehicular travel detected by an acceleration sensor installed within the tire into a pre-leading-edge region R1, which precedes a leading-edge peak appearing at the leading edge of contact patch, a leading-edge region R2, which is the region constituting the leading-edge peak, a pre-trailing-edge region R3, which falls between the leading-edge peak and a trailing-edge peak appearing at the trailing edge, a trailing-edge region R4, which is the region constituting the trailing-edge peak, and a post-trailing-edge region R5, which follows the trailing-edge peak; (b) obtaining from the time-series waveform: a band value P 11 selected from a band of 2 kHz to 8 kHz of the pre-leading-edge region R1, a band value P 12 selected from a band of 0.5 kHz to 1.5 kHz of the pre-leading-edge region R1, a band value P 21 selected from a band of 1 kHz to 3 kHz of the leading-edge region R2, and a band value P 51 selected from a band of 1 kHz to 4 kHz of the post-trailing-edge region R5; and a band value P 11 selected from a band of 2 kHz to 8 kHz of the pre-leading-edge region R1, a band value P 12 selected from a band of 0.5 kHz to 1.5 kHz of the pre-leading-edge region R1, a band value P 21 selected from a band of 1 kHz to 3 kHz of the leading-edge region R2, and a band value P 51 selected from a band of 1 kHz to 4 kHz of the post-trailing-edge region R5; and (c) estimating whether the road surface during vehicular travel is a snowy road or not, based on the magnitude of the band values P 11, P 12, P 21, and P 51,