Weather Term 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 | Measure of how hot or cold the air is (°C or °F) | Influences comfort, clothing, and energy usage | Extreme temperatures 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 |
| Atmospheric Pressure | Weight of air above you (hPa or mb) | Indicates weather patterns — falling = storms, rising = fair weather | Standard sea-level pressure ≈ 1013 hPa |
| Barometric Trend | Change in atmospheric pressure over time | Falling pressure indicates storms; rising indicates fair weather | — |
| Dew Point | Temperature at which air becomes saturated and dew forms | Higher dew point means more moisture and muggy conditions | Predicts fog, frost, and condensation |
| Relative Humidity | % moisture compared to the maximum possible at a temperature | Key for comfort and precipitation prediction | — |
| Absolute Humidity | Actual amount of water vapour in the air (g/m³) | Used in scientific and HVAC calculations | — |
| 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 cooling by sweating | Above 40°C can be dangerous |
| Heatwave | Prolonged period of excessive heat | Causes health risks, droughts, and energy 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 (mm/hour) | Predicts flooding risk and storm severity | High rates overwhelm drainage systems |
| Snowfall | Frozen precipitation (cm or inches) | Impacts transport, infrastructure, and sports | — |
| Hail | Frozen precipitation in 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 objects can be seen (km or miles) | Poor visibility affects driving and aviation | Reduced by fog and heavy rain |
| Fog | Thick cloud near the ground reducing visibility | Dangerous for driving and aviation | Occurs when air cools to its dew point |
| Solar & air quality | |||
| Solar Radiation | Sunlight energy reaching Earth (W/m²) | Affects temperature, plant growth, and solar power | Varies by time, season, and cloud cover |
| UV Index | Scale (0–11+) of ultraviolet radiation strength | High UV causes skin damage and cancer risk | Guides sun-protection measures |
| Air Quality Index (AQI) | Measure of air pollution levels | High AQI harms health, especially sensitive groups | — |
| Weather systems & fronts | |||
| Cold Front | Boundary where cold air replaces warm air | Brings storms, heavy rain, and temperature drops | — |
| Warm Front | Boundary where warm air replaces cold air | Brings steady rain and gradual warming | — |
| Cyclone / Hurricane | Large storm system with strong winds and heavy rain | Causes severe damage and flooding | — |
| Tornado | Violently rotating column of air from storm to ground | Extremely destructive and dangerous | — |
| Thunderstorm | Storm with thunder, lightning, heavy rain, sometimes hail | Can lead to flash flooding and severe alerts | — |
| Lightning | Sudden electrostatic discharge during storms | Causes fires, injuries, and power outages | — |
| Blizzard | Severe snowstorm with strong winds and low visibility | Dangerous for travel and outdoor activities | — |
| Drought | Prolonged period of little or no rainfall | Impacts agriculture, water supply, and ecosystems | — |