Assign each ace to its appropriate season. Here are my correspondences.
Ace of Clubs or Ace of Wands = Spring
Ace of Hearts or Ace of Cups = Summer
Ace of Diamonds or Ace of Pentacles = Fall
Ace of Spades or Ace of Swords = Winter
With your timing question in mind, shuffle and go through the deck card by card until you come to your first Ace. The Ace that appears reflects the season during which the event may happen.