Basic weather definitions

‘Weather’ is a term that we all comfortably use in day to day language to mean anything to do with the conditions that we experience when we step outside the house, but it’s often confused with the word ‘climate’. In order to understand how the outdoor environment impacts upon bushwalking, it’s important to understand the difference.

The National Oceanic and Atmospheric Administration (NOAA) is the leading American scientific agency that focuses on the conditions of the atmosphere and oceans.

NOAA defines weather as:

“The state of the atmosphere with respect to wind, temperature, cloudiness, moisture, pressure, etc. Weather refers to these conditions at a given point in time (e.g., today’s high temperature), whereas Climate refers to the “average” weather conditions for an area over a long period of time (e.g., the average high temperature for today’s date)”.

Weather consists of short-term changes in the conditions of the atmosphere measured in minutes, days and months. Climate refers to the long-term records, trends and averages of the atmospheric behaviour in a place measured in years.

Both are described in terms of variable conditions such as temperature, wind velocity, precipitation (including rain, snow, sleet, hail), humidity, and barometric pressure. And both weather and climate can vary dramatically across the earth – think of how different the northern hemisphere Christmas is to our Australian one!

An easy way to remember the difference is that the climate is what you expect (e.g. a sweltering summer) and the weather is what you get, like a hot day with late-afternoon thunderstorm.

When planning a hiking trip months in advance, climate information is useful at the beginning of the planning process. When the days draw nearer, however, actual weather forecasts become more important than climate averages.