Weather Terms Reference Table
30 key meteorological terms — what they are, why they matter, and useful notes
| Term | What it is | Why it matters | Additional info |
|---|---|---|---|
| Atmospheric basics | |||
| Temperature | How hot or cold the air is (°C or °F) | Influences comfort, clothing, and energy usage | Extremes cause heat stress or hypothermia |
| Humidity | Amount of water vapour in the air (%) | Affects comfort, health, and evaporation rates | Important for HVAC and fog prediction |
| Relative Humidity | Moisture as a % of the maximum possible at that temperature | Key for comfort and predicting precipitation | — |
| Absolute Humidity | Actual water vapour in the air (g/m³) | Used in scientific and HVAC calculations | — |
| Atmospheric Pressure | Weight of the air above you (hPa or mb) | Indicates weather patterns — falling = storms, rising = fair weather | Standard sea-level pressure ≈ 1013 hPa |
| Barometric Trend | How atmospheric pressure is changing over time | Rapid fall signals approaching storms; rise signals clearing | — |
| Dew Point | Temperature at which air becomes saturated and dew forms | Higher dew point = more moisture in the air; feels muggy | Predicts fog, frost, and condensation |
| Wind | |||
| Wind Chill | Perceived temperature when wind removes body heat | Critical for outdoor safety in cold conditions | Strong winds make cold feel much colder |
| Wind Gust | Sudden brief increase in wind speed | Can damage structures and affect aviation | — |
| Heat & “feels like” | |||
| Heat Index | “Feels like” temperature combining heat and humidity | High humidity reduces the body’s ability to cool by sweating | Above 40°C can be dangerous |
| Heatwave | Prolonged period of excessive heat | Health risks, droughts, and energy grid strain | — |
| Precipitation | |||
| Precipitation | Any water falling from the sky — rain, snow, hail | Essential for water cycles and agriculture | Can cause flooding or icy conditions |
| Rain | Liquid precipitation measured in mm | Important for agriculture, drainage, and planning | Heavy rain can cause flooding |
| Rain Rate | Intensity of rainfall in mm/hour | Predicts flooding risk and storm severity | High rates overwhelm drainage systems |
| Snowfall | Frozen precipitation measured in cm or inches | Impacts transport, infrastructure, and outdoor activities | — |
| Hail | Frozen precipitation falling as ice pellets | Damages crops, vehicles, and property | — |
| Sky & visibility | |||
| Cloud Cover | Fraction of sky covered by clouds (% or oktas) | Influences sunlight, temperature, and solar radiation | — |
| Visibility | Distance at which objects can be clearly seen (km) | Poor visibility affects driving and aviation safety | Fog and heavy rain are the main causes |
| Fog | Thick cloud at ground level reducing visibility sharply | Dangerous for road and air travel | Forms when air cools to dew point |
| Solar & radiation | |||
| Solar Radiation | Sunlight energy reaching Earth’s surface (W/m²) | Affects temperature, plant growth, and solar power output | Varies by time of day, season, and cloud cover |
| UV Index | Scale (0–11+) of ultraviolet radiation strength | High UV causes skin damage and raises cancer risk | Guides sun protection decisions |
| Air Quality Index | Measure of air pollution levels | High AQI harms health, especially for sensitive groups | — |
| Weather systems & fronts | |||
| Cold Front | Boundary where advancing cold air replaces warm air | Brings storms, heavy rain, and sudden temperature drops | — |
| Warm Front | Boundary where advancing warm air replaces cold air | Brings steady rain and gradual warming | — |
| Cyclone / Hurricane | Large rotating storm system with strong winds and heavy rain | Causes severe damage and widespread flooding | — |
| Tornado | Violently rotating column of air extending from storm to ground | Extremely destructive; one of nature’s most dangerous events | — |
| Thunderstorm | Storm with thunder, lightning, heavy rain, and sometimes hail | Can trigger flash floods and severe weather alerts | — |
| Lightning | Sudden electrostatic discharge during a storm | Can cause fires, injuries, and power outages | — |
| Blizzard | Severe snowstorm with strong winds and very low visibility | Dangerous for all travel and outdoor activity | — |
| Drought | Prolonged period of little or no rainfall | Impacts agriculture, water supply, and ecosystems | — |
Weather Terms Infographic
Key meteorological terms at a glance
Temperature
How hot or cold the air is (°C or °F). Influences comfort, clothing, and energy usage.
Humidity
Amount of water vapour in the air (%). Affects comfort, health, and evaporation rates.
Atmospheric Pressure
Weight of air above you (hPa). Falling pressure signals storms; rising signals fair weather.
Dew Point
Temperature at which air becomes saturated. Predicts fog, frost, and condensation.
Heat Index
“Feels like” temperature combining heat and humidity. Above 40°C can be dangerous.
Wind Chill
Perceived temperature when wind removes body heat. Critical for outdoor safety in cold conditions.
Wind Gust
Sudden brief increase in wind speed. Can damage structures and affect aviation.
Solar Radiation
Sunlight energy reaching Earth (W/m²). Affects temperature, plant growth, and solar power.
UV Index
Scale (0–11+) of ultraviolet radiation strength. High UV causes skin damage — use sunscreen.
Rain
Liquid precipitation measured in mm. Heavy rain can cause flooding and landslides.
Snowfall
Frozen precipitation (cm). Impacts transport, infrastructure, and outdoor activity.
Hail
Frozen precipitation as ice pellets. Damages crops, vehicles, and property.
Cloud Cover
Fraction of sky covered by clouds (oktas). Influences sunlight, temperature, and solar radiation.
Fog
Thick cloud at ground level. Forms when air cools to dew point — dangerous for travel.
Tornado
Violently rotating column of air extending to the ground. Extremely destructive.
Cyclone / Hurricane
Large rotating storm system with intense winds and heavy rain. Causes severe flooding.
Thunderstorm
Storm with thunder, lightning, and heavy rain. Can trigger flash floods and severe alerts.
Lightning
Electrostatic discharge during storms. Can cause fires, injuries, and power outages.
Blizzard
Severe snowstorm with strong winds and very low visibility. Dangerous for all travel.
Drought
Prolonged period of little or no rainfall. Impacts agriculture, water supply, and ecosystems.
