My friend Russ and I have talked several times about the arrival of spring. He says that in his neck of the woods (New Brunswick, Canada), spring comes "under the snow": the first signs appear at places where the snow has started to melt and you can see the ground below. (He said it much better in a piece he wrote years ago - I'd hoped it was on his website, but it isn't . . . yet . . . )

Myself, I think that spring comes down from the sky. And this year, as always, it has begun to show itself now - mid-February. I can't quite identify how I know this - but the birds know it, too; they've been singing quite cheerfully and insistently for the past few days, and I know it isn't just the weather, because although it's been sunny, it's been darned cold. But the sky has been the delicate robin's-egg, pastel blue of April and May, and something about the slant of the light, and the particular fluff to the clouds . . . La crepuscule has been lasting satisfyingly longer; we now have a noticeable twilight instead of the abrupt curtain-drop of darkness that we get at sunset in December and January. This year, as always, we have turned the corner of winter - up there in the sky, no matter what's happening here on the ground. The equinox is a handy marker of spring for the mathematically-minded among us, but the birds and I think differently.

For the past few days, I've been thinking that the weather folks ought to have a Sun Index. There's a heat index during the summer, and a wind chill in the winter - both of which irritate me beyond belief, as they are both variations on "Oh, my god, it's awful out there! Stay indoors!" Not to mention, who the heck knows what a particular temperature "feels like"? It's a case of precision outstripping accuracy, if you ask me. (Just the sort of gobbledygook that leads people to innumeracy, but that's a rant for a different day.)

So I think we need an optimistic indicator in the other direction, and I'm proposing the "Sun Index." When it's in the teens outside and the sun is shining brightly, it feels a lot warmer than when it's overcast. I would love to hear some weather forecaster say, "It's 15 outside - but it feels like 30!" Because that's sure how it felt to me today . . .