Newfoundland's coast was dotted with small French and English communities, with some fishing stations occupied seasonally by fishermen from Europe. Both sides had fortified their principal towns, the French at Plaisance on the western side of the Avalon Peninsula, the English at St. John's on Conception Bay. During King William's War, d'Iberville had destroyed most of the English communities in 1696-97, and the island again became a battleground in 1702. In August of that year, an English fleet under the command of Commodore John Leake descended on the outlying French communities but made no attempts on Plaisance. During the winter of 1705, Plaisance's French governor Daniel d'Auger de Subercase retaliated, leading a combined French and Mi'kmaq expedition that destroyed several English settlements and unsuccessfully besieged Fort William at St. John's. The French and their Indian allies continued to harry the English throughout the summer and did damages to the English establishments claimed at £188,000. The English sent a fleet in 1706 that destroyed French fishing outposts on the island's northern coasts. In December 1708, a combined force of French, Canadian, and Mi'kmaq volunteers captured St. John's and destroyed the fortifications. They lacked the resources to hold the prize, however, so they abandoned it, and St. John's was reoccupied and refortified by the English in 1709. English fleet commanders contemplated attacks on Plaisance in 1703 and 1711 but did not make them, the latter by Admiral Walker in the aftermath of the disaster at the mouth of the St. Lawrence.
Question: St. John's was unsuccessfully besieged in what time of year?
Answer: winter