Conditions of the Italian Campaign
The Allied Forces faced many different problems. As they landed at Sicily they faced tough resistance from the Italians, but overall it was ideal conditions for fighting. They fought in beautiful spring weather with no rain, no insects and no mosquitos. The worst conditions occurred later in the battles of Cassino and Anzio when Italy was cold and rainy.
... In Sicily, the nineteen scattered airdromes that had worried Eisenhower so much the previous spring increased to thirty-two by early May. But as Spaatz aimed the weight of his bombers against those Sicilian objectives, the Axis withdrew it's aircraft to safer rearward fields." - General Omar Bradely, G.O.C. U.S. II Corps
No war was ever fought, I think, in more ideal weather than the Sicilian Campaign. The soft spring lay upon land like a benediction..." - General Matthew B. Ridgeway