Sub-freezing temperatures Tuesday night into Wednesday are expected to give way to a more seasonable end to the first full week of October in Maine.

The National Weather Service placed all of coastal Maine under a frost advisory from midnight until 8 a.m. Wednesday, with expected lows between 30 and 35 degrees. Meanwhile, interior Cumberland and Androscoggin counties were placed under a freeze warning, with temperatures as low as 25 degrees expected in the same timeframe.

Areas further inland, including Fryeburg, Rumford, Rangeley and Jackman, were also expected to see temperatures fall to between 25 and 30 degrees overnight, according to the weather service.

Despite the equally cold temperatures elsewhere in the state, Hunter Tubbs, a meteorologist at the weather service’s Gray office, explained that the advisories are limited to coastal regions as the growing season remains active there until Oct. 11.

“Some areas are already past the growing season, so we don’t have (advisories) out for those areas,” he said in a phone call Tuesday.

He said this is around the time when meteorologists would expect the region to begin experiencing frosty overnight temperatures. The weather service advises residents to cover or bring inside any sensitive outdoor plants.

Tubbs said Tuesday night into Wednesday would likely see the coldest temperatures of the week, with the remainder of the week looking more seasonable.

“That’s just because we had a strong cold front that came through, and that allowed for strong northwesterly winds to bring down colder air from Canada,” Tubbs explained.

Wednesday’s highs are expected to be in the high 50s and low 60s across southern and central Maine, according to the weather service.

But temperatures are expected to rise Thursday, with some areas, including Portland and Lewiston, slated to be as warm as 70 degrees. Tubbs said the projected uptick in temperatures is thanks to warmer air pushing in from the southwest.

Then, the weather service forecasts high temperatures will dip back down to the low 60s — and even to the low 50s in some western Maine communities — Friday and Saturday. Things are expected to begin warming up again on Sunday, with highs potentially reaching 70 degrees once more on Monday.

Meanwhile, low temperatures are expected to remain fairly steady: Southeastern regions, including Greater Portland, can expect lows in the mid-to-low 40s Thursday through the beginning of next week, while areas farther north and west can expect lows in the mid-to-high 30s.

Some showers could be in the mix across the western mountains late this week, according to the weather service, but Tubbs said it isn’t expected to amount to much.

“As of right now, it doesn’t look like anything significant in terms of rainfall,” he said Tuesday.

On Tuesday morning, the Mount Washington Observatory reported the first measurable snowfall of the season atop New Hampshire’s tallest peak, with just over a half-inch of snow accumulating in a 24-hour period. It noted that a wind gust of 110 miles per hour was recorded.