The display of the WS-1150 needs good batteries to work optimally. We use 1,5V batteries. 

If you have used for example 1,2V rechargeable batteries, the clarity may decrease. 

If you place the weather station on a table/desk and sit down facing it, it will have the correct angle and you will see that the display is very clear. 

If you look at the image from the side, it may indeed be that the readability decreases. This can happen with an LCD display.