Guide

Right outsideSky

Sirius, the brightest star, found by following Orion's belt

December to March

Sirius is the brightest star in the night sky, and the three stars of Orion's belt point straight to it. When Sirius is low, its light crosses a long stretch of moving air, so it flickers and seems to flash red, blue and green.

Why this time of year

By about 9pm in mid December, Sirius is about 10 degrees up in the southeast. By mid January it is about 20 degrees up in the southeast at 8pm, by mid February it is nearly due south at 8pm, and by mid March it sits due south at 8pm. From this far north it never climbs much more than a third of the way up the sky, so it always shines through a lot of air.

How to notice it

  1. On a clear evening, find Orion: three bright stars close together in a short, straight row, his belt.
  2. Follow the line of the belt down and to the left until you reach a very bright white star. That is Sirius.
  3. In December and January catch it while it is still low in the southeast, with no streetlight in your eyes, and watch it for a slow count of thirty. Look for quick flashes of red, blue and green.
  4. Later in the season, or later the same night when it has climbed higher, look again and compare. Higher up it usually shines steadier and whiter.

Try this with kids: Count the colors you see Sirius flash. Is it the star changing, or the air between you and the star?

Safety

  • Winter nights get cold fast when you stand still, so dress warmer than a walk would need.

Sources

  • earthsky.orgEarthSky: Orion's Belt points to it; rises in the southeast, arcs across the south, sets southwest; rises mid-evening in December; often flickers with many colors, especially easy to notice when low; by early April moving toward sunset glare.
  • stardate.orgStarDate (McDonald Observatory): Sirius light passes through a thick layer of air so it twinkles fiercely, changing colors rapidly; look southeast in the evening, good view by 8 or 9 p.m.
  • aa.usno.navy.milUSNO: 9pm EST Dec 15 2026 at 42.4 N, Sirius altitude 10.3, azimuth 124.
  • aa.usno.navy.milUSNO: 8pm EST Jan 15 2027, Sirius altitude 19.0, azimuth 137.
  • aa.usno.navy.milUSNO: 8pm EST Feb 15 2027, Sirius altitude 29.8, azimuth 167.
  • aa.usno.navy.milUSNO: 8pm EDT Mar 15 2027, Sirius altitude 30.8, azimuth 181.

Checked against these sources on November 3, 2026.

In the guide for December, January, February, March

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