Follow below steps to get rain effect on your image

  1. Open any image & create new layer on it.
  2. Press ‘D’ to set default foreground & background colors
  3. For new layer select Filter -> Render -> Clouds & change its opacity to 60 (preferable 60 you can change accordingly)
  4. select Filter -> Noise -> Add Noise
    • Amount = 60
    • Distribution = Gaussian
    • Check ‘Monochromatic’
  5. Select Filter -> Blur -> Motion Blur (Rain and its amount)
    • Angle = 73 deg
    • Distance = 10
  6. Change the new layer’s blending mode to ‘Screen’