Unofficially this is our “Halloween Weekend” (and definitely the last weekend in October), and all watchful weather eyes are on alert for what the forecast is for trick or treating.

Basically, it’s all up in the air (isn't it always?).

But first,  the wise folks at The Weather Network say that though this weekend will start off well on Saturday, “soaking rains and gusty winds will come courtesy of a tropical infusion by Sunday.”

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After that, the only thing certain is an Oct. 31 forecast that mentions a significant storm and potential snow by next week.

First, to the weekend.

A tropical depression (named Tropical Storm Olga) that formed in Gulf of Mexico is going to affect our weather bringing lots of rain once it arrives on Sunday. Forecasters, via a special weather statement,  warn of 25 plus mm of rain across southern Ontario and maybe 50 mm or more in some areas, possibly starting Saturday night. Winds might hit 60km/h.

The good news? It will be mild. Saturday's high is 10 degrees, climbing to 16 degrees on Sunday.

After we say goodbye to Olga’s handiwork, “fair and mild conditions return for the start of next week.” Then, “a potentially potent system” of Arctic air may be on the way for Halloween.

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According the Weather Network’s Dr. Doug Gillham: "A classic fall storm will track along the boundary between the warm and cold air. However, there is still a lot of uncertainty as to where that boundary will be.

“There are some computer models that keep the boundary to our north and west, which would allow temperatures to climb into the upper teens and lower 20s across the Golden Horseshoe for Wednesday and Halloween."

However, other forecasts, says Gillham, show that we could get much colder temperatures and lake effect snow for Halloween. Trick or treat!

And eventually, that colder weather, like November, is on its way, with highs in single digits starting this Thursday. Actually, Accuweather is predicting  that a cold and stormy winter is in the cards for Ontario.

Brrrr. Stay tuned and get that Halloween costume ready.