Click at Photo (Large View)
Noted: To make rainy effect, actually it is depends at your photo resolution and size. You can see and follow my tutorial as a guideline and process flow. But some setting maybe not suitable for your picture.
Thanks and Regards...
Original Photo
Final Image
Step 1
Open the photo and create a new layer, then change mode Normal to Screen.
Step 2
Go to Edit > Fill
Step 3
Go to Filter > Noise > Add Noise.. This setup depends at your photo resolution
Step 4
Go to Image > Adjustment > Levels...Click Auto and click OK
Step 5
Go to Filter > Blur > Motion Blur
Step 6
Go to Image > Adjustment > Levels
Step 7
Go to Filter > Other > Maximum
Step 8
Go to Filter > Blur > Gaussian Blur
Step 9
Change the opacity. You can decrease opacity to 50& to 80%. Depends your photo resolution.
Final Image