Weather and Climate
FoundationWeather is the air over a short time; climate is the long-term average — thermometers measure temperature, rain gauges measure rainfall.
- Weather is short-term; climate is the long-term average.
- Weather elements include temperature, rainfall, humidity, wind direction and speed.
- Thermometers measure temperature; rain gauges measure rainfall.
文體小知識：說明文配上例子，把天氣與氣候的分別、天氣要素和量度工具一一講明。
§Text Passage
1Before going out, we always want to know whether it will be hot or rainy today — that is caring about the weather. Weather is the state of the air over a short time in a place: sunny today, rainy tomorrow, cool in the morning and hot in the afternoon. Weather changes fast and can be completely different within a few hours.
2Climate is different. Climate is the average weather pattern of a place worked out from long-term records. For example, Hong Kong has a subtropical climate: hot and humid summers, cool and dry winters. Deserts have a dry climate with little rain all year. For weather we ask what today is like; for climate we ask what most years are like — never mix the two.
3Weather has several main elements. Temperature tells how hot or cold the air is, measured with a thermometer. Rainfall tells how deep the fallen rain would be over a period, measured with a rain gauge. Humidity tells how much water vapour is in the air; when it is high we feel sticky. Wind has a direction and a speed, telling us where the wind comes from and how hard it blows.
4Places differ greatly in weather. Hong Kong is humid and rainy in summer, with thunderstorms and typhoons. Northern cities such as Harbin have freezing winters with snow and ice. Deserts have a big difference between day and night temperatures and are dry all year. Weather offices collect data from many places and make weather reports and forecasts to help us plan each day.
5Weather shapes our daily life: take an umbrella on rainy days, dehumidify in damp weather, wear more to keep warm in cold spells. Learn to read the weather report and know the climates of different places, and you will know whether to pack T-shirts or a coat when travelling — be a smart little weather watcher!
1Summary 重點摘要
Weather is the air over a short time; climate is the long-term average — thermometers measure temperature, rain gauges measure rainfall.
2Vocabulary cards Vocabulary
The state of the air in a place over a short time, such as today's sunshine, rain, heat or cold.
The average weather pattern of a place observed over many years.
How hot or cold the air is, measured with a thermometer.
The depth of rain that falls over a period, measured with a rain gauge.
The amount of water vapour in the air; high humidity feels sticky.
A tool for measuring how hot or cold the air is.
A tool for measuring rainfall, like a graduated cylinder.
A tropical storm with fierce wind and heavy rain, common in Hong Kong in summer and autumn.
A place that is dry all year with little rain and a big difference between day and night temperatures.
Information and forecasts about the weather issued from observation data.
3Step by step Steps
- Step 1: Tell weather from climateWeather and climate are both about the air, but their timescales differ. Weather is the condition of a place over a short time — hot with thunderstorms this afternoon, cooler and cloudy tomorrow morning — and it can change within hours. Climate is the average pattern worked out from more than thirty years of records; Hong Kong's climate is hot and humid in summer and cool and dry in winter. Remember the rhyme: weather asks about today, climate asks about year after year. Think first whether you mean today or the long-term pattern, and you will never mix them up.
- Step 2: Know the main weather elementsTo describe weather accurately, use its elements. Temperature is how hot or cold the air is, such as a high of thirty-one degrees today. Rainfall is how much rain falls over a period, such as twenty millimetres in the past hour. Humidity is the water vapour in the air; in a Hong Kong summer it often tops eighty per cent and feels sticky. Wind has direction and speed, such as a light breeze. Put the elements together — thirty-three degrees, high humidity, light wind, showers in the afternoon — and you have a full weather description.
- Step 3: Measure weather with toolsEach element has its own instrument. Temperature is measured with a thermometer kept in a louvred shelter away from direct sunlight so the reading is accurate. Rainfall is measured with a rain gauge, a marked cylinder that collects rain so you can read the depth in millimetres. Humidity is measured with a hygrometer; wind direction with a wind vane and wind speed with an anemometer. The observatory runs automatic stations collecting data day and night. You can be a little weather watcher at home: put a simple rain gauge on the balcony, record it daily, and after a month you will know which days had the most rain.
- Step 4: Compare weather in different placesWeather differs greatly around the world. Hong Kong lies in the subtropics: hot, humid summers with thunderstorms and typhoons, cool, dry winters. Northern cities such as Harbin can fall to twenty degrees below zero in winter, with snow and ice for ice festivals. Desert places such as the Sahara are dry all year, blazing hot by day and cool at night. Before travelling, check the local climate and forecast, then you will know whether to pack T-shirts or a thick coat, and whether to bring rain gear.
- Step 5: Learn to read the weather reportWeather reports are compiled by the weather office from observations everywhere, giving current weather and forecasts for the next few days. When reading a report, look out for: the temperature range, such as twenty-six to thirty degrees; the weather symbols — a sun for sunny, clouds for cloudy, an umbrella for rain; the relative humidity and wind; and special notices such as thunderstorm warnings or typhoon signals. Read the report each morning and you will know whether to take an umbrella or a jacket, and weekend plans can be made with peace of mind.
- Step 6: Weather and our livesWeather touches our lives every day. In heavy rain we carry umbrellas and wear waterproof shoes; in damp weather clothes dry slowly and homes run dehumidifiers; in cold spells we put on more clothes and take care of the elderly; when a typhoon comes, schools may close and fishing boats rush back to harbour. Farmers watch the weather to sow and harvest, hikers watch it to plan routes, and flights depend on it too. Spend one minute a day on the weather report and jot it in a diary — you will soon know your local weather like a friend.
5Worked example Example
Mei says: It is so hot in Hong Kong today! Lung says: Hong Kong's climate is hot and humid in summer. Which one is describing weather and which climate? And is Harbin's snowy winter weather or climate?
- Weather means the air over a short time; climate means the long-term average over many years.
- Mei is talking about how hot it is right now, a short-time condition, so it is weather.
- Lung sums up Hong Kong's summers over many years, a long-term pattern, so it is climate.
- Harbin is cold and snowy every winter; as a repeating pattern, it is a feature of climate.
- Answer: Mei is describing weather, because she means the condition over a short time. Lung is describing climate, the long-term pattern of Hong Kong's summers. Harbin's cold, snowy winters happen year after year, so they are a feature of climate.
6Common mistakes Mistakes
7Quick check Quick check
Q1What is the biggest difference between weather and climate?
Q2Which tool measures rainfall?
Q3Besides humid, rainy summers, what weather event is common in Hong Kong in summer?
Q4What do we call the amount of water vapour in the air?
Q5Harbin often has snow in winter — is that weather or climate?
8Recap Recap
- Weather is short-term; climate is the long-term average.
- Weather elements include temperature, rainfall, humidity, wind direction and speed.
- Thermometers measure temperature; rain gauges measure rainfall.
- Hong Kong is humid and rainy; northern cities have snow; deserts are dry.
- Check the weather report before going out to plan the day well.