@JeanDeff
Hi
As Buzz mentioned above its not a good idea as it can corrupt your SD card. I have a weather station that runs continuously that has suffered several power cuts and hasn't corrupted but a colleague at work who has the same setup gets a corrupted card every time.
It would appear some SD cards are better than others and if it helps the one in my weather station is a transcend one and has been in use for four years.
Cheers
Paul