The climate in a particular part of the world will influence its vegetation and wildlife, so is fundamental to life on Earth. Find out about factors influencing weather and climate and how to interpret climate data.
Weather and climate
Weather describes the condition of the atmosphere. It might be sunny, hot, windy or cloudy, raining or snowing. Climate means the average weather conditions in a particular location based on the average weather experienced there over 30 years or more. Global climate zones with similar flora, fauna and climate are called biomes.
The weather takes into account the temperature, precipitation, humidity andatmospheric pressure of the part of atmosphere (air) closest to the surface of the earth.The weather is constantly changing as temperature and humidity change in the atmosphere. Landmasses, such as the British Isles, experience constantly changing weather conditions.
Climate refers to what is expected to happen in the atmosphere rather than the actual conditions. It is possible for the weather to be different from that suggested by the climate.
- Climatic conditions in an area can be affected by the landscape, relief and activities taking place (both human and natural). Climate can alter over time and space.
- Within a climatic region, the climate may vary from place to place - eg the top of a hill, the sunny side of a hill, the shaded side of a hill and the bottom of a hill. These areas with their small variations are called microclimates.
The science of monitoring and studying the atmosphere and predicting its weather and climate is called meteorology. People who study the weather and climate are known as meteorologists.
Global distribution of climates
Climates are influenced by many factors, such as proximity to the equator or the poles and proximity to the sea, as well as things like ocean currents, atmospheric pressure belts and prevailing winds. A place's climate influences the types of vegetation and animals that live there. It is possible to divide the world into a number of climatic zones or biomes, each with their own characteristic climate, vegetation and wildlife.
Factors affecting climate
Latitude or distance from the equator
Temperatures drop the further an area is from the equator due to the curvature of the earth. In areas closer to the poles, sunlight has a larger area of atmosphere to pass through and the sun is at a lower angle in the sky. As a result, more energy is lost and temperatures are cooler.
In addition, the presence of ice and snow nearer the poles causes a higheralbedo, meaning that more solar energy is reflected, also contributing to the cold.
The effect of the Sun's rays
Altitude or height above sea level
Locations at a higher altitude have colder temperatures. Temperature usually decreases by 1°C for every 100 metres in altitude.
Distance from the sea
Oceans heat up and cool down much more slowly than land. This means that coastal locations tend to be cooler in summer and warmer in winter than places inland at the same latitude and altitude. Glasgow, for example, is at a similar latitude to Moscow, but is much milder in winter because it is nearer to the coast than Moscow..
Ocean currents
Britain has a maritime climate. A warm ocean current called the North Atlantic Drift keeps Britain warmer and wetter than places in continental Europe.
The North Atlantic Drift
Prevailing wind
The prevailing wind is the most frequent wind direction a location experiences. In Britain the prevailing wind is from the south west, which brings warm, moist air from the Atlantic Ocean. This contributes to the frequent rainfall. When prevailing winds blow over land areas, it can contribute to creating desert climates.