Guide

Right outsideWeather

How to find low pressure with your back to the wind

All year

Stand with your back to a steady wind and the center of low pressure lies off to your left. Near the ground it sits a little ahead of straight left, because friction turns the wind slightly toward the low.

Why this time of year

This rule, named for a 19th-century Dutch scientist, gives you a rough compass to the low. It works the same way in every season, so you only need a breezy day with a steady direction.

How to notice it

  1. Pick a spot in the open, away from tall trees, and wait for a steady stretch of wind rather than a gust. Face into the wind to feel it, then turn around so it blows on your back.
  2. Point your left arm out to the side, then swing it a little forward. The center of low pressure is somewhere out along that direction.
  3. Now point your right arm out to the side and a little back. High pressure lies somewhere that way.
  4. Later, find the low on a weather map or forecast and see whether it matches where you pointed. Treat the rule as a rough guide, not an exact bearing.

Try this with kids: Turn your back to the wind and point left. Where do you think the low pressure is?

Word to know: A “low” is an area where air pressure is lower than the air around it; air flowing into it rises, which can bring clouds and rain.

Safety

  • Do not stand under large branches or dead trees in strong wind.
  • Skip this on days with a wind warning or damaging gusts; stay indoors and do it from a window by watching trees sway.

Sources

  • nsidc.orgNSIDC glossary: in the Northern Hemisphere, back to the wind, low pressure on your left and high pressure on your right. Ballot was a 19th century Dutch climatologist.
  • noaa.govNOAA JetStream: winds circle counter-clockwise around lows; at the surface friction makes wind cross isobars slightly toward the low center. Air converging on a low is forced to rise and cools, which can lead to clouds and precipitation.
  • eas.ualberta.caUniversity of Alberta lecture notes: Buys-Ballot's law applied to winds aloft; back to the winds aloft, lower pressure lies to your left.

Checked against these sources on October 9, 2026.

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