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.