fermented in under 5 days . is this right

[Frisp]

On Friday Past I mixed up my coopers Dark al Using normal sugar. I stuck it in the airing cupboard which I later found was running just short of 25 C. I left it there for the temperature to match that or the Cupboard befor adding the yeast.
The OG was 1042

By morning the brew was a Foam fest and it was off and running like an olympian.
it continues to froth and started slowing yesterday. I noticed this moning that the foam had gone and the brew no longer looked so alive. So I dropped the old Hydromyter in and the current reading is an unbelievable 1006.
Can this be right in just roughly 4 .5 days since the yeast went in?
I know the cupboard is on the warm side but can it possibly have fermented out in so little time.
And yes Im reading the Hydrometer properly.

[MartialAnt]

Is your brew still at 25c when taking the reading? If it is then you will get a false reading. Not by much tho.
Fill up your trial jar if you have one & run cold water against the side till it drops to 20c then the reading will be accurate.
I did a coopers lager at 25c (thats what the instructions say) it frothed out of the FV. That also fermented in a matter of days. Tasted crap but got me pissed.

[Frisp]

Fair point about the temp It still brings it in about 1007.
If you had a similar experience then I will believe the readings.
And at the end of the day as long as the result undermines my sensible side who cares........ Tasting good wil be a bonus but on my first brew Non essential.
I have found a nice spot in one of my rooms which is between 19 and 22 C so the next brew will go there to see what happens.

[Minus The Bear]

you will see a great improvement when you ferment at the cooler temp, it will take longer but will defo be worth it.