The Ottoman army that arrived in late September had been somewhat depleted during the long advance into Austrian territory, leaving Suleiman short of camels and heavy artillery.
Many of his troops arrived at Vienna in a poor state of health after the tribulations of a long march through the thick of the European wet season.
Of those fit to fight, a third were light cavalry, or Sipahis, ill-suited for siege warfare.
Three richly dressed Austrian prisoners were dispatched as emissaries by the Sultan to negotiate the city's surrender; Salm sent three richly dressed Muslims back without a response.

As the Ottoman army settled into position, the Austrian garrison launched sorties to disrupt the digging and mining of tunnels below the city's walls by Ottoman sappers, and in one case almost capturing Ibrahim Pasha.
The defending forces detected and successfully detonated several mines intended to bring down the city's walls, subsequently dispatching 8,000 men on 6 October to attack the Ottoman mining operations, destroying many of the tunnels, but sustaining serious losses when the confined spaces hindered their retreat into the city.

More rain fell on 11 October, and with the Ottomans failing to make any breaches in the walls, the prospects for victory began to fade rapidly.
In addition, Suleiman was facing critical shortages of supplies such as food and water, while casualties, sickness, and desertions began taking a toll on his army's ranks.
The janissaries began voicing their displeasure at the progression of events, demanding a decision on whether to remain or abandon the siege.
The Sultan convened an official council on 12 October to deliberate the matter.
It was decided to attempt one final, major assault on Vienna, an "all or nothing" gamble.
 Extra rewards were offered to the troops.
However, this assault was also beaten back as, once again, the arquebuses and long pikes of the defenders prevailed.

Unusually heavy snowfall made conditions go from bad to worse.
The Ottoman retreat turned into a disaster with much of the baggage and artillery abandoned or lost in rough conditions, as were many prisoners.
The Ottoman army that arrived in late September had been somewhat depleted during the long advance into Austrian territory, leaving Suleiman short of camels and heavy artillery. Many of his troops arrived at Vienna in a poor state of health after the tribulations of a long march through the thick of the European wet season. Of those fit to fight, a third were light cavalry, or Sipahis, ill-suited for siege warfare. Three richly dressed Austrian prisoners were dispatched as emissaries by the Sultan to negotiate the city's surrender; Salm sent three richly dressed Muslims back without a response.
As the Ottoman army settled into position, the Austrian garrison launched sorties to disrupt the digging and mining of tunnels below the city's walls by Ottoman sappers, and in one case almost capturing Ibrahim Pasha. The defending forces detected and successfully detonated several mines intended to bring down the city's walls, subsequently dispatching 8,000 men on 6 October to attack the Ottoman mining operations, destroying many of the tunnels, but sustaining serious losses when the confined spaces hindered their retreat into the city.
More rain fell on 11 October, and with the Ottomans failing to make any breaches in the walls, the prospects for victory began to fade rapidly. In addition, Suleiman was facing critical shortages of supplies such as food and water, while casualties, sickness, and desertions began taking a toll on his army's ranks. The janissaries began voicing their displeasure at the progression of events, demanding a decision on whether to remain or abandon the siege. The Sultan convened an official council on 12 October to deliberate the matter. It was decided to attempt one final, major assault on Vienna, an "all or nothing" gamble.  Extra rewards were offered to the troops. However, this assault was also beaten back as, once again, the arquebuses and long pikes of the defenders prevailed.
Unusually heavy snowfall made conditions go from bad to worse. The Ottoman retreat turned into a disaster with much of the baggage and artillery abandoned or lost in rough conditions, as were many prisoners.
Siege of Vienna