weather Archives - Free ZIMSEC & Cambridge Revision Notes

Frost/Snow and Hail

By garikaib|2025-02-12T09:05:00+02:00February 12th, 2025|Notes, O Level Geography, Ordinary Level Notes, Weather and Climate|

A house and vehicle covered in snow. Image by Novinite. ZIMSEC O Level Geography Notes: Frost/Snow and Hail.

Snow/Frost

Caused by a sudden fall or drop in temperature.
With snow ice crystals are formed in the atmosphere.
When these small ice crystals collide with […]

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Pressure systems

By garikaib|2025-02-12T09:10:04+02:00February 12th, 2025|O Level Geography, Weather and Climate|

The world's pressure belts The world’s pressure belts and winds ZIMSEC O Level Geography Notes: Pressure

Pressure

Air has weight and therefore exerts pressure, called atmospheric pressure onto the earth’s surface.
The pressure is not the same for all regions nor is it the same for any one region all the time that […]

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Introduction to weather and climate

By garikaib|2025-02-12T08:59:57+02:00February 12th, 2025|O Level Geography, Weather and Climate|

Rainy Weather. Image by Sodahead. ZIMSEC O Level Geography Notes: Introduction to Weather and Climate

Weather-the state of the atmosphere at a particular place and time as regards heat, cloudiness, dryness, sunshine, wind, rain, etc. The weather is all around us, all the time. It is an […]

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Temperature

By garikaib|2025-02-12T09:05:32+02:00February 12th, 2025|O Level Geography, Weather and Climate|

Six's thermometer Six’s thermometer ZIMSEC O Level Geography Notes: Temperature

The daily maximum and minimum temperatures are measured using Six’s thermometer (pictured above).
It was invented by James Six a British scientist hence the name Six’s thermometer.
It is also known as the Maximum and Minimum thermometer.
It is housed in a Stevenson’s screen.
Diurnal […]

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Stevenson’s screen

By garikaib|2025-02-12T09:07:02+02:00February 12th, 2025|O Level Geography, Weather and Climate|

An open Stevenson screen showing the instruments it houses. Image by Hubhomedesign. ZIMSEC O Level Geography Notes: Stevenson Screen

A Stevenson screen is a prominent feature on most weather stations.

It is used to house weather instruments, for example the […]

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Humidity

By garikaib|2025-02-12T09:08:25+02:00February 12th, 2025|O Level Geography, Weather and Climate|

Wet and dry bulb thermometer. Image by TradeIndia ZIMSEC O Level Geography Notes: Humidity

-a quantity representing the amount of water vapor in the atmosphere.

It is measured using a hydrometer.
The wet and dry bulb thermometer is also known as a psychrometer.
Weather satellites can […]

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Wind direction and speed

By garikaib|2025-02-12T09:14:35+02:00February 12th, 2025|O Level Geography, Weather and Climate|

A cup anemometer and windvane. Image by Noaa.gov. ZIMSEC O Level Geography Notes: Wind direction and speed.

Wind is the movement of air across the earth’s surface due to differences in pressure between two regions. Air moves from high pressure regions to low […]

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Sunshine

By garikaib|2025-02-12T09:16:02+02:00February 12th, 2025|O Level Geography, Weather and Climate|

A sunshine recorder. Image by Rfuess-Mueller. ZIMSEC O Level Geography Notes: Sunshine

It has a glass sphere surrounded by a metal frame.
On the frame is attached a sensitive card.
The sphere focuses the sun’s rays onto the card.
As the sun moves across the sky it burns […]

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Orographic/Relief Rainfall

By garikaib|2025-02-12T09:31:47+02:00February 12th, 2025|O Level Geography, Weather and Climate|

Aberfoyle Tea Estate in the Eastern Highlands is one of the places that receive a lot of Relief rainfall. Image Credit Buckinghambirding. Aberfoyle Tea Estate in the Honde Valley Eastern Highlands is one of the places that receive a lot of Relief rainfall. Image Credit Buckinghambirding. ZIMSEC O Level Geography Notes: […]