Can magnets get weaker if they are left out through the year in cold or hot weather?

Answer 1

every permanent magnet has a Curie temperature where all magnetism is erased. By definition permanent magnets have Curie temperatures above that of common ambient temps. However, the closer you get to the Curie temp, the shorter will be the life of a permanent magnet.

As a reference, the Curie point of soft iron is around 1000K.

Answer 2

I searched the Internet using Google and found some answers:
http://www.science.ca/askascientist/viewquestion.php?qID=587
http://www.phy6.org/earthmag/magnQ&A4.htm

Still, I have not found one that confirm my memory on magnets in sensitive instrument where magnets play a key role (an inclinometer for example.) Even when kept in acceptable operating limits (not to abuse an expensive intrument), the device needs to be recalibrate periodically because the magnet does lose its strength gradually over time. In most daily applications, the reduction in magnet strength are not noticeable (less than .001% per year.)

My experience with a u shaped steel magnet was that I can give it a strong shock with a hammer without breaking it. Afterward, I noticed a substantial reduction in magnet strength.

Also, a strong magnet in my sensitive voltmeter loses more 10% of its strength immediately after I removed it from the meter movement. I believe this magnet was magnetized to its peak strength (after it was installed) when the air gap between the poles is minimum. As soon as the air gap between the poles increases due to disassembly, the magnetic strength reduces and can not recover by itself when reassemled.

Answer 3

heat can weaken a magnet and metals can take the magnetism from the magnet of course making the metal magnetized

Answer 4

any server change in temp. that takes magnets out of their balance decrease their attraction force.

Answer 5

yes,offcoarse

Answer 6

YES

Answer 7

Heat can do that.