Why pressure matters
Deer can't read a forecast, but they feel the weather change. The hours before a front arrives and the stretch right after it passes are often the most active of the week. Many hunters see more daylight movement when pressure is climbing back toward the high 29s and 30s after a storm.
What to watch
The trend matters more than the exact number. A swing of a tenth of an inch of mercury or more over a few hours is significant. Log the pressure and its direction (rising, falling, steady) every time you sit. After a season or two, your own sightings will show which conditions matter on your property.
How to use it
Save your best stands for the day a cold front clears, when pressure is rising, temperatures drop and wind is steady. If you only have a few days to hunt during the rut, spend them there.