My F-I-L served in a US Army engineer aviation battalion attached to the 3rd Infantry Division. They built or repaired a number of airfields in Sicily in 1943. I have 2 CDs of the battalion records.
Short answer to your question – Boca di Falcon, Gerbini (Main) and Catania were all weather airfields prior to the Sicily Invasion.
Below are some snips from the battalion records regarding Sicilian airfields. Most were for dry weather use only. (There was only one rainstorm during the campaign.) The battalion supported 3rd Infantry, the British, and a French artillery battery. Other EABs (809th & 814th) supported other US divisions so the list of Sicilian airfields is incomplete.
Pre-invasion planning contemplated the preparing of this field as the initial mission of the battalion. A personal reconnaissance of the field, however, showed the construction only about ten per-cent complete and in such a dispersed manner that it was impractical to convert it into an airfield except as a major project. The equipment arrived at the site about 1700 hours on D plus 1 and by 1700 hours on D plus 2, the field was operational. C Co performed Air Corps service functions, refueling and re-arming planes, until D plus 8. The Licata field was improved … at which time the field consisted on only one dry weather runway 200 feet by 6,000 feet with taxiways and hardstandings for 90 planes.
One platoon of C Co arrived at Torrenti Communeli, which was situated 13 km west of Gela and constructed one dry weather runway 200 ft by 6,000 ft with taxiways and handstandings for 50 airplanes.
One platoon from C Co arrived at this site which was 7 miles east of Agrigento, and constructed a dry weather runway 150 ft by 4,500 ft with taxiways and hardstandings for 85 airplanes. The runway could not be lengthened.
Boca di Falcon
The field was an all over air field which had been rendered inoperational by the standing of 55 gallon drums all over the field. These drums were tested for mines and the field completely cleared in 2 ½ hours. The field was a rocky, all weather field with a rough surface, pitted as a result of Allied bombing. Several small hangers and an extensive barracks area were badly damaged by the withdrawing of enemy and civilians. Subsequent work on the field consisted of widening the 150 ft runway 50 feet and extending its length of 3,000 ft by 1,000 additional ft. This extension had a width of 150 ft. Further improvement on the field consisting of providing an asphalt runway had been started when the responsibility for the work was transferred to the 814th Engineer Aviation Battalion. On 28 August 1943, B Co left for San Antonio, Sicily.
One platoon of B co arrived and constructed a dry weather runway 150 ft by 6,000 ft with taxiway and hardstandings for 40 planes. The size of this field was very limited prohibiting expansion.
C Co arrived at this air field, which was originally an old German 3,000 ft landing strip. The soil was found to be too loose and sandy, hence another strip was located 200 yards inland, still parrelling (sic) the coastline. The field consisted of a runway 150 ft by 5,140 ft and taxiways and hardstandings for 81 planes. It was used as a base for fighter planes and air-evacuation of the wounded.
A Co arrived and started construction on a dry weather runway 150 ft by 4,000 ft with taxiways and hardstandings for 50 planes.
B Co arrived and constructed a dry weather runway 150 ft by 4,500 ft with taxiways and hardstandings for 100 planes. The field was located in the Milazzo plain area and was cleared from a grape vineyard. The loose dust presented quite a problem. However, the many captured tank trailers used for continuous sprinkling aided considerably in combating this condition.
C Co arrived and constructed a dry weather runway 150 ft by 4,500 ft with taxiways and hardstandings for 75 planes. The loose dust presented quite a problem here. Bunker oil was made available by the British Navy at Syracusa. However, this long haul was deemed impracticable and after approximately 13,000 gallons of oil had been spread, the use of water was resumed.
C Co arrived at Gerbini Main airfield, which was an all weather field with paved runways and taxiways. The work consisted of normal maintenance of a bombed field and tearing down damaged hangers, clearing out dispersal revetments and maintaining taxiways and roads. A study was made of the housing facilities with the idea of making this a permanent all-weather bombing base.
The first platoon of A co arrived and constructed a dry weather runway 150 ft by 3,500 ft with taxiways and hardstandings for 100 planes. The field was located in a grape vineyard…. The removal of the vines and the cropping of the roots resulted in a very serious dust hazard which was alleviated somewhat by water, at all times operations permitted.
The 3rd platoon of Co A arrived and constructed a dry weather runway 150 ft by 3,800 ft with taxiways and hardstandings for 100 planes. The field, like the other in the area, was cleared from a vineyard. The loose dust created quite a hazard, which was alleviated considerably by the continuous sprinkling of the airfield with water.
B Co arrived and took over the project from the British airfield construction group. Upon arrival, the airport was in operation. The airfield was typical of all other bomb damaged permanent airfields in that an indefinite amount of work could be performed to increase the value of the field.
Source: 'History of the 815 Engineer Aviation Battalion', Maxwell AFB.
The 815th worked on 13 airfields in 5 weeks. They removed 6,000 land mines without one injury.
Palermo was a dry weather field which was converted to a 4,000 ft all weather field by C Co, 814th EAB. A magnetic device was utilized to clear the field of bomb fragments which could puncture aircraft tires. (If I remember correctly a B17 carrying Monty overshot the runway and crashed at Palermo. Monty dusted himself off and went to meet with Gen. Patton.)