下面是完整代码:
```python
# Plot Seattle data, setting data appearance
ax.plot(seattle_weather["MONTH"], seattle_weather["MLY-PRCP-NORMAL"], color='b', marker='o', linestyle='--')
# Plot Austin data, setting data appearance
ax.plot(austin_weather["MONTH"], austin_weather["MLY-PRCP-NORMAL"], color='r', marker='v', linestyle='--')
# Call show to display the resulting plot
plt.show()
```