Weather Terms Reference Table
| Term | What it is | Why it matters | Additional Info |
|---|---|---|---|
| Temperature | Measure of how hot or cold the air is (°C or °F). | Influences comfort, clothing, energy usage. | Extreme temps cause heat stress or hypothermia. |
| Humidity | Amount of water vapour in the air (%). | Affects comfort, health, 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. |
| Dew Point | Temp at which air becomes saturated and dew forms. | Higher dew point = more moisture, feels muggy. | Predicts fog, frost, condensation. |
| Wind Chill | Perceived temp when wind removes body heat. | Critical for outdoor safety in cold conditions. | Strong winds make cold feel much colder. |
| Heat Index | “Feels like” temp combining heat and humidity. | High humidity reduces cooling by sweating. | Above 40°C can be dangerous. |
| Rain | Liquid precipitation (mm). | Important for agriculture, drainage, planning. | Heavy rain can cause flooding. |
| Rain Rate | Intensity of rainfall (mm/hour). | Predicts flooding risk and storm severity. | High rates overwhelm drainage systems. |
| Solar Radiation | Sunlight energy reaching Earth (W/m²). | Affects temperature, plant growth, solar power. | Varies by time, season, cloud cover. |
| UV Index | Scale (0–11+) of ultraviolet radiation strength. | High UV causes skin damage, cancer risk. | Guides sun protection measures. |
| Visibility | Distance objects can be seen (km or miles). | Poor visibility affects driving and aviation. | Fog and heavy rain reduce visibility. |
| Cloud Cover | Fraction of sky covered by clouds (% or oktas). | Influences sunlight, temperature, solar radiation. | |
| Precipitation | Any water falling from sky—rain, snow, hail. | Essential for water cycles, agriculture. | Can cause flooding or icy conditions. |
| Snowfall | Frozen precipitation (cm or inches). | Impacts transport, infrastructure, sports. | |
| Fog | Thick cloud near ground reducing visibility. | Dangerous for driving and aviation. | Occurs when air cools to dew point. |
| Wind Gust | Sudden brief increase in wind speed. | Can damage structures, affect aviation. | |
| Relative Humidity | % moisture compared to max possible at temp. | Key for comfort and predicting precipitation. | |
| Absolute Humidity | Actual water vapour amount (g/m³). | Used in scientific and HVAC calculations. | |
| Heatwave | Prolonged period of excessive heat. | Health risks, droughts, energy strain. | |
| Cold Front | Boundary where cold air replaces warm air. | Brings storms, heavy rain, temp drops. | |
| Warm Front | Boundary where warm air replaces cold air. | Brings steady rain, gradual warming. | |
| Cyclone/Hurricane | Large storm system with strong winds, heavy rain. | Severe damage and flooding. | |
| Tornado | Violently rotating column of air from storm to ground. | Extremely destructive and dangerous. | |
| Lightning | Sudden electrostatic discharge during storm. | Can cause fires, injuries, outages. | |
| Thunderstorm | Storm with thunder, lightning, heavy rain, sometimes hail. | Can lead to flash floods, severe alerts. | |
| Hail | Frozen precipitation as ice pellets. | Damages crops, vehicles, property. | |
| Blizzard | Severe snowstorm with strong winds, low visibility. | Dangerous for travel and outdoor activities. | |
| Drought | Prolonged period of little/no rainfall. | Impacts agriculture, water supply, ecosystems. | |
| Air Quality Index | Measure of air pollution levels. | High AQI harms health, especially sensitive groups. | |
| Barometric Trend | Change in atmospheric pressure over time. | Falling = storms; rising = fair weather. |
Weather Terms Infographic
🌡️
Temperature
Measure of 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.
🔥
Heat Index
“Feels like” temperature combining heat and humidity. Above 40°C can be dangerous.
❄️
Wind Chill
Perceived temperature when wind removes body heat. Important for outdoor safety.
🌧️
Rain
Liquid precipitation (mm). Heavy rain can cause flooding and landslides.
🌪️
Tornado
Violently rotating column of air. Extremely destructive and dangerous.
☁️
Cloud Cover
Fraction of sky covered by clouds (%). Influences sunlight and temperature.
⚡
Lightning
Electrostatic discharge during storms. Can cause fires and power outages.
