Tuesday in Washington in a sense was both warm and cool, and perhaps in that way it provided the perfect symbol of a month often thought to be named for the Roman deity Janus.

After all, many of us think of Janus as the possessor of two faces, a representative of the dual nature of things, the binary aspect of reality. Judged by the thermometer, Tuesday in Washington also showed us two faces.

On one hand, we may call Tuesday as cold a day as we have had in Washington all year, with a low temperature of 29 degrees.

So Tuesday did its part, perhaps, to uphold the reputation of January as our coldest month. Besides Tuesday, the month’s only other 29-degree reading was made Monday.

Otherwise, the mercury has remained above freezing every minute of every other January day except for Saturday, when it settled exactly on the freezing point at 32 degrees.

But Tuesday also represented warmth, the sort of warmth that we may be fortunate enough to find on a winter’s day.

Tuesday’s claim to be warm rests on the afternoon high of 49. That made the day the third-warmest of January so far.

At 49 degrees, Tuesday’s high has been exceeded only twice this month: on Jan. 2, when it was 58, and on Sunday, when it was 50.

We must concede Tuesday had its morning chill. But to see the day only in those terms seemed unfair to the afternoon’s sunny benevolence. The sunshine helped provide warmth six degrees above what the statistics entitled us to expect. For Jan. 12 in Washington, National Weather Service figures indicate that the normal high temperature is only 43.

As a result, Tuesday could easily be regarded as showing fidelity to Janus, offering us two meteorological faces in a single January day and teaching us that one day may serve two meteorological masters.