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The perturbed-angular-correlation (PAC) technique has been used to study the electric quadrupole interaction (QI) of the nuclear probe 181Ta in yttrium metal and yttrium-hydrogen solid solutions α-YHx with 0⩽x⩽0.2. The temperature dependence of the quadrupole frequency νq of 181Ta in yttrium metal, measured in the range 290 K⩽T⩽1700 K, follows the linear relation νq(T) = νq(0)(1-AT) with νq(0) = 423(3) MHz and A = 4.74(4)×10-4 K-1. The absorption of hydrogen enhances the temperature dependence of the QI: the parameters νq(0) and A of the linear temperature variation of the 181Ta QI in α-YHx measured between 25 K and 1000 K for 0⩽x⩽0.2 both increase with increasing concentration x. These trends are consistent with the anionic model of the electronic state of hydrogen in rare earth metals. At T⩾500 K a dynamic QI caused by diffusing hydrogen has been observed. The activation energy for hydrogen jumps in α-YH0.10 deduced from the temperature dependence of the quadrupole relaxation rate is Ea = 0.49(15) eV.