Temperature of boiled water in kettle/microwave

[HeavenK76]

ok, so I boiled a full kettle and measured the temp and got a reading of 87C then I boiled a cup in a microwave and got the same exact reading which makes me think water boils at 100C, so why these readings.
Assuming the temps are correct (I'm using this laser probe from my husband's restaurant) and we wait 30 min to cool down water for feeds it would be too cool.
Rather just make up feeds straight away then.
I read water bubbles before reaching the full 100C and you should let the water come to a full boil which is hotter than just bubbling water, if that makes sense?

Any thoughts?

I would have thought that pure H2O boils at 100 deg, but that typical tap water has various impurities in it that affect the boiling point.

Also, the leaving it to cool for 30 mins thing is actually "no more than 30 mins". So if you're worried you could leave it for less time. If you've got the thermometer you could try leaving the water for 30 mins and see what the temp is.

Yes, it's 'no longer than 30 minutes', based on boiling one litre of water. The water needs to be 70degrees or more when making up formula to kill any bacteria they may be in the powder. You could make up the bottle sooner than 30 minutes, just be careful not to scald yourself and ensure it's sufficiently cooled before offering to baby.