Hazy sunshine will predominate over southwestern Connecticut for most of the day. And the warmer-than-usual temperatures, combined with humidity, will make it feel more like early September rather than late October.

Meanwhile, a strong low-pressure system in the upper Mississippi Valley is churning north to Ontario. While this won't affect the region directly, it's dragging behind it a cold front that may trigger showers after midnight tonight and into tomorrow.

Still, tomorrow should be warm and muggy as well. But there will be a chance of rain and thunderstorms as Wednesday progresses, and there could be heavy downpours.

By Thursday, the cold front should settle over the region with high temperatures nearly 20 degrees cooler than today's high. Skies, however, should be sunny.

As of now, the National Weather Service predicts a dry, cool early evening for Halloween trick-or-treaters.

The sun will set today at 5:56 p.m. after 10 hours and 39 minutes of sunlight. Sunrise tomorrow will be at 7:18 a.m.

High tide today is at 1:47 p.m. in Bridgeport and 1:50 p.m. in Stamford/Greenwich.

Here's more details from the National Weather Service forecast:

Today: Mostly sunny after early-morning clouds, with a high near 69 degrees. Southwest wind between 5 and 9 mph. Chance of precipitation is 20 percent.

Tonight: Showers possible, and patchy fog after 2 a.m. Otherwise, mostly cloudy, with a low around 59 degrees. South wind around 11 mph. Chance of precipitation is 60 percent. New rainfall amounts of less than a tenth of an inch possible.

Wednesday: Showers and possibly a thunderstorm. High near 69 degrees. Southwest wind between 10 and 14 mph. Chance of precipitation is 80 percent. New rainfall amounts between a quarter and half of an inch possible.

Wednesday night: Showers likely and possibly a thunderstorm before 10 p.m., then a chance of showers between 10 p.m. and 2 a.m. Cloudy, then gradually becoming partly cloudy, with a low around 55 degrees. West wind between 5 and 7 mph. Chance of precipitation is 60 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Thursday: Mostly sunny, with a daytime high near 70. West wind between 8 and 17 mph.