Defina o tamanho da fonte xaxis pandas

plt.figure()
plt.rcParams.update({'font.size': 22}) # must set in top

ax1 = df_plot.plot(x='wind_direct',y=plot_columns,figsize=(30,18),linewidth=5,kind='line',legend=True, fontsize=16)
ax1.legend(loc=2,fontsize=20)
ax1.set_ylabel('kw',fontdict={'fontsize':24})
ax2 = ax1.twinx()
ax3 = df_plot.plot(x='wind_direct',y=counts_columns,figsize=(30,18),kind='bar',legend=True, ax=ax2, fontsize=16)
ax3.set_title(title,pad=20, fontdict={'fontsize':24})
ax3.set_ylabel('counts',fontdict={'fontsize':24})
ax3.legend(loc=1,fontsize=20);
Nice Narwhal