Resources

Glossary

Departure from Normal (Dep): Difference between a day’s average temperature and the long-term average for that date.
Trace (T): A precipitation amount too small to measure accurately.
Relative Humidity: Moisture in the air relative to the maximum possible at that temperature, in percent.
Sea Level Pressure: Pressure adjusted to mean sea level so stations at different elevations can be compared.
Weather Codes: FG = fog, BR = mist, HZ = haze, RA = rain.