Even before this month and year come to an end, some things can be said about them with arithmetical and meteorological certainty.

On New Year’s Eve, when December 2012 concludes, it will go into the books as warmer than a normal Washington December. In fact, figures will show it to be much warmer. Perhaps five degrees warmer, or even more.

That can be said without full information about Sunday’s weather, despite Sunday’s wind, and without considering whatever conditions might characterize the 31st of December. It reflects the fact that through Saturday night, Washington’s average temperature this month, as measured at Reagan National Airport, has been more than six degrees above normal.

Sunday, of course, may not have seemed particularly warm. Yet, as of 4 p.m., it was three degrees above normal. At that point, the day’s high temperature was 42 degrees, and the low, measured in the morning, was 37.

However, strong winds raked the Washington region for much of the day Sunday. At National, gauges measured a peak gust of 49 mph. The peak wind was 36 mph.

That wind, coming out of the northwest, did more than raise whitecaps on the Potomac River.

It put the wind-chill index into play, making the Dec. 30 experience seem chillier than the high and low temperatures, taken by themselves, might have suggested. This chill sensation — and whatever shivering it might have caused — was purely meteorological in origin, and had nothing to do with the psychological sense of being perched on the edge of a fiscal cliff.

Or a few hours away from the crucial confrontation between the Washington Redskins and the Dallas Cowboys.

Of course, National has a reputation as one of the principal centers of warmth in the Washington region. Spots more remote from the District and the Potomac might experience lower temperatures.

“Still have not gotten above freezing today in Western Loudoun,” read a comment sent to The Washington Post’s Capital Weather Gang site.

The temperature was reported to be 30 degrees about 2 p.m. But it was picturesque.

“The water dripping from the small leak in one of the gutters on the front porch has turned the branches of the bush it is hitting into an icicle wonderland,” it was reported.

Washington might have been a little warmer than some parts of the region. But the wind was apparently widespread.

“That wind cuts your face up like a cold knife,” read another message sent to the Weather Gang site. Yet another comment told of deciding to make it an indoor day.

“We stay in today,” the comment read. “ . . . watch things blow past windows.”

In turning out to be far warmer than normal, December contrasted sharply with the month before. November, for the first and apparently only time this year, recorded an average temperature that was below normal.

Previous months in 2012 had been warmer than normal, but November went into the records as three degrees cooler.

Aside from that deviation, Washington has been uniformly warmer in every season. It was warmer in the summer and it was warmer in the winter months.