Certainty about predictions of the future has always been close to zero. If you take a person from an appropriate time and ask them what the future will look like in 1000, 100 or even 20 years then their predictions will bear little resemblence to what actually occurs.

As humans we have a tendancy to make linear future predictions based on past observations. Over the timescales that matter significant effects occur from previously unseen kinds of events that become important via interactions with other events.

The important measurement would be what the length of the event horizon - the length of time before our predictions rapidly decrease to zero certainty. In a singularity we would expect that length of time to decrease close to zero. What has it been historically? I would claim that 5-10 years is a difficult period to make meaningful predictions about. I think that 20 years has proven to be very difficult but possible in the past. I am unaware of any 100+ year predictions that have landed with better than random chance.

Interestingly I think we are entering a period where 5 years will be the upper bound, and even predictions over shorter 2-3 year timespans are going to become difficult.