Does a player who draws from Howling Mine during another player's turn count as drawing for their own card draw triggers?

Drawing a card is a specific game action defined in CR 120.1: a player puts the top card of their library into their hand. The rules make no distinction about whose turn it is when this action occurs. A draw is a draw, full stop.

Howling Mine (and similar 'draw at the beginning of each player's draw step' effects) causes each player to draw one card at the start of that player's draw step. So during your opponent's turn, Howling Mine causes you to draw a card during your opponent's draw step (CR 120.2 covers additional card draws granted by effects).

If you control a permanent with a triggered ability that reads 'Whenever you draw a card,' such as Thought Monitor or Psychic Corrosion's related effects, those triggers watch for you performing the draw action. Since you are the one drawing from Howling Mine even on an opponent's turn, the trigger condition is met and the ability triggers (CR 603.2).

Concrete example: It is your opponent's turn. During their draw step, Howling Mine's triggered ability resolves and you draw a card. You also control Alhammarret's Archive, and you have a 'whenever you draw a card' trigger from Otherworldly Gaze or similar. That trigger fires because you drew the card, even though it is not your turn.

The only relevant condition is whether the triggered ability says 'whenever you draw' (it cares about who draws) versus 'whenever a player draws' (which would cover any draw). Both fire in this situation, but for different reasons — either way, Howling Mine's draw on your opponent's turn counts toward your own card-draw triggers (CR 603.2, 120.1).