[axkingofallmedia]

We can all agree that the average boiling temperature for water is 100 C and that depends on the altitude. Water at an altitude above sea level boils at a temperature < 100C and vice versa.

Having said that, we can also agree that covering a pot makes the water boil faster, but does it make the water boil at a lower temperature? Or does this not affect the temperature?

[The_MD]

If you put a lid on a container you prevent water vapour from escaping.  Well, restrict really.  This does two things.

First you increase the internal pressure of the container a bit.

Secondly, by holding water vapour within the pot, you are also holding in its energy, rather than allowing it to escape to atmosphere. 

Does either of these things sound like it might speed up a pot boiling?

[newtonjc]

Wouldn't isolating the environment just increase the rate at which temperature rises? I feel like the boiling point would stay the same, and the time it takes to meet BP would be reduced.

[enahs]

A pressure cooker is a well sealed container. It works by using the steam you produce to increase the pressure to increase the boiling point of water.

It all depends on how good your lid is. So, probably the average lid on a normal pot I am use to might increase the pressure by a tiny fraction of a percent; so yes it will technically increase the boiling point of the water. But it would be such an insignificant amount it would be really hard to measure.