UTCI Simulation - Weird results for April

I tried to run the UTCI simulation for the deck spaces of a high rise building considering the floor materials and along with the shading elements. When I ran the results for the month of October the results were fine but with the same model and the same grasshopper script the results for April seems more weird. Based on the comments from certain forums I also checked the data from the EPW file but every thing remains the same and I’m not able to figure out what is wrong in the April Simulation. I have attached the images of the April result.

I hope someone can help me to solve this issue. Thanks in Advance.