By Terry Eliasen, Meteorologist, WBZ-TV Exec. Weather Producer

BOSTON (CBS) – Never has a first frost been so anticipated by so many.

With the fear of Eastern Equine Encephalitis (EEE) and West Nile Virus causing so many communities to cancel evening activities, we are badly in need of some good old fashion freezing temperatures.

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The average first frost for the suburbs has actually already passed.

In an average year, most of the ‘burbs have their first 32 degree night around October 6th.

For Boston that date is much later, averaging about a month later, November 7th.

Despite some cooler than normal daytime temperatures of late, we have yet to plunge to the freezing mark overnight.

This is all about to change.

Several cold fronts are about to pass through New England and each will work to lower temperatures more and more as cold air will begin to pour in from Canada.

The first cold front is set to cross this evening, and with skies clearing out later tonight, temperatures will drop through the 40’s in most locations.

Thursday night and Friday morning are going to be even colder than tonight, however some clouds are likely to enter on Friday morning and prevent the temperatures from dropping to their potential bottom.

Lows early on Friday are projected to be in the upper 30’s and low 40’s.

Should those clouds come in a bit later than currently forecast, some scattered frost is possible Friday morning.

A cold frontal passage on Friday will seal the deal.  The floodgates will truly open up from Northern Canada and by Saturday morning nearly all of the suburbs will drop below 32 degrees.

Low temperatures will range from about 25-32 on average with a few exceptions in the city of Boston and over Cape Cod.

The hardtop of the city streets trap daytime heat very well, making it hard to radiate that heat into space.  Therefore, Boston will likely only dip to around 40 degrees on Saturday morning.

Over the Cape, with the influence of mild ocean waters, temperatures will stick mainly in the upper 30’s and 40’s except for some grassy inland spots which could radiate down to the low 30’s.

So the big question for many will be – does this mean that all the mosquitoes will die off and EEE and West Nile fears will end?

Unfortunately this is not likely to be a kill-all hard frost.

To rid ourselves of all mosquitoes we typically need a few successive nights of well-below freezing temperatures lasting for several hours.

The frost on Saturday will kill many but not all mosquitoes.

However, if you have any plants growing outdoors, you will need to protect them, or better yet take them inside for the night.

Make sure you pick the last few tomatoes off the vine, they would likely not survive the night.

One final quick note.

If it seems like the cold air is coming a bit earlier this year, you are right, at least compared to last year.

In 2011, most of the suburbs did not have their first frost until October 27th or 28th and in Boston we didn’t see a frost until November 24th, about a month behind schedule.

You can follow Terry on Twitter at @TerryWBZ.

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