What's The Longest Time You Can Spend in a Lucid Dream?

It's potentially the same as any normal dream: on any given night, your longest dream period is typically 35-40 minutes in the morning, shortly before you wake up.

However there can be exceptions where the dream time extends longer than usual, and especially during lucid dreams the physiological variables are ideal for prolonged dreaming.

My longest lucid dream appeared to last around an hour, based on my looking at the time before a Wake Induced Lucid Dream, and then waking up and checking the time again.

It occurred in the morning after I'd already slept a number of hours, which is the best time to lucid dream for most people with normal sleep cycles. Of course, not all lucid dreams last that long: more often my lucid dreams are an estimated 10-20 minutes long in real time. This is usually plenty to fulfil my lucid intention of the day!

Also consider REM is the stage of sleep in which the majority of dreaming occurs. On average, we have 2-3 hours of REM sleep per night.

Sleep happens in 'cycles' that tend to last about 90 minutes - and REM happens towards the end of these. In fact, the sleep cycles towards the end of the night tend to have more REM activity.

So taking this into account the longest theoretical lucid dream would be about 2 hours long, but in practice this is rare and most tend to be 5-45 minutes at most.