Half-hourly values of the critical frequency of the ionospheric F region, foF2, obtained at Wuhan Ionospheric Observatory (geographic 114.4¿E, 30.6¿N; 45.2¿ dip), China, during the period from 1957 to 1991 have been used to investigate the solar activity dependence of the monthly median foF2, and to construct single-station models using Fourier expansion and cubic-B splines approaches. The climatological models incorporate local standard time, month, and solar cycle variations of foF2. Statistical analyses show that, over Wuhan, the monthly median foF2 has a significantly nonlinear dependence on the current and historical solar activities. Introducing the monthly median F107 in the prior month can significantly improve the accuracy of our models. Thus the complex influence of solar activities is approximately expressed by a general nonlinear function. Our models are in good agreement with observations, with standard deviations between about 0.26 to 0.58 MHz. In contrast, the IRI model tends to overestimate foF2 over Wuhan and has a lower accuracy with standard deviations between about 0.5 to 1 MHz.