will Comet Lemmon be a naked eye object when it becomes visible in the Northern Latitudes?

Yes, if it's going to be at peak brightness at the end of March and magnitude 2 or 3 (which is pretty bright), it should easily be visible to the unaided eye in April.

Just to let you know Bellatrix in Orion is magnitude 2 (approximately) and iota Orionis (third star in the sword of Orion) is magnitude 3 both of which are visible even in most cities although you have to go out into the country to see them really clearly.

So the comet will be naked eye visible but if you live in the city it will be pretty unimpressive.

Well, ..., comet Lemmon at last check iwill be a naked eye object at mag 2 or 3. BTW, The comet is green because of the gases intercting with the solar wind. The "jets spewing from the comet's nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space." See below

Comet ISON (Nov 2013) is expected to be a bright naked eye object as well.

Maybe.

It is predicted to be about magnitude 3 at perihelion.

But it then has to move away from the sun.

We won't know how bright it will be till it emerges from the sun's glare in early April.

But it is only likely to be quite dim -- it will not be very bright.

At the moment it is only visible from the southern Hemisphere and nothern hemisphere south of USA.

yes, if the comet remains stable, it will be seen with the naked eye.Now you can watch it in Microscopium.