Temperature
Heat Energy in the Atmosphere
Energy Source
Solar Radiation - Sun provides virtually all heat energy to Earth's atmosphere and surface
Measurement
Celsius & Fahrenheit - Temperature scales measuring molecular motion
Global Range
-129°F to 134°F - Extreme temperatures from coldest to hottest places
What is Temperature?
Temperature is a measure of the average kinetic energy of molecules in the atmosphere. Higher temperatures mean faster molecular motion, lower temperatures mean slower motion. Temperature is not the same as heat - heat is the transfer of thermal energy. Temperature is fundamental to weather and climate, affecting precipitation, evaporation, atmospheric stability, and all weather phenomena.
Temperature Scales
Celsius (°C)
Standard: Used in science and most countries
Water Freezing: 0°C (32°F)
Water Boiling: 100°C (212°F)
Absolute Zero: -273.15°C
Fahrenheit (°F)
Standard: Primarily used in USA and Caribbean
Water Freezing: 32°F (0°C)
Water Boiling: 212°F (100°C)
Comfort Range: 65-75°F (18-24°C)
Kelvin (K)
Scientific: Absolute temperature scale, starts at absolute zero
Water Freezing: 273.15 K (0°C)
Water Boiling: 373.15 K (100°C)
Formula: K = C + 273.15
Global Temperature Patterns
Equatorial Regions
Temperature: Warm year-round, 75-85°F (24-29°C) typical
Reason: Direct overhead sun year-round, minimal seasonal variation
Climate: Tropical rainforests, tropical savanna, high convection
Variation: More variation in daily temperature than seasonal
Mid-Latitudes
Temperature: Highly variable, -20 to 95°F (-29 to 35°C)
Reason: Moderate sun angle, strong seasonal variation
Climate: Temperate forests, four seasons, storm systems
Variation: Greatest seasonal temperature ranges
Polar Regions
Temperature: Extremely cold, -60 to 32°F (-51 to 0°C)
Reason: Low angle sun, ice and snow reflect heat
Climate: Tundra, glaciers, minimal precipitation
Variation: Extreme seasonal variation despite low absolute temps
Altitude Effects
Temperature Lapse Rate: Temperature drops ~3.5°F per 1,000 feet
Mountains: Summit temperatures much colder than base
Atmosphere: Troposphere cools with height, stratosphere warms
Example: Denver (5,280 ft) averages 15°F colder than coastal areas
Temperature Extremes & Records
Hottest Temperatures
- • Hottest: 134°F (56.7°C) - Death Valley, CA (1913)
- • Hottest inhabited: 129°F (54°C) - Kuwait (2016)
- • Reliable high: 128°F (53.3°C) - Multiple locations
- • Heat stress and dehydration
- • Increased mortality rates
- • Infrastructure damage (rails bend)
- • Wildfire risk dramatically increases
Coldest Temperatures
- • Coldest: -129°F (-89.2°C) - Vostok, Antarctica (1983)
- • Northern: -90°F (-67.7°C) - Oymyakon, Russia
- • Coldest inhabited: -89°F (-67.1°C) - Oymyakon
- • Frostbite in minutes at extreme cold
- • Hypothermia risk increases
- • Machinery fails, metals become brittle
- • Snow and ice accumulation
Effects of Temperature
Atmospheric Stability
Warm Air: Less dense, rises, creates instability and convection
Cold Air: Dense, sinks, creates stability and suppresses storms
Inversion: Warm layer over cold layer traps pollution
CAPE: Temperature difference drives thunderstorm potential
Water Phase Changes
Evaporation: Warmer = faster water to vapor conversion
Condensation: Cooling causes vapor to become liquid droplets
Freezing: Below 0°C (32°F) water becomes ice
Sublimation: Ice directly becomes vapor without melting
Biological Impacts
Metabolism: Cold-blooded animals slow down in cold
Photosynthesis: Optimal range 75-85°F (24-29°C)
Migration: Animals move to find optimal temperatures
Hibernation: Extended dormancy in extreme cold seasons
Human Comfort
Comfort Range: 65-75°F (18-24°C) for most people
Heat Index: Combines temperature and humidity
Wind Chill: Wind makes cold feel colder
Clothing Needs: Varies with temperature and activity level
Temperature & Climate Change
Global temperatures have increased approximately 1.8°F (1°C) since pre-industrial times, with most warming occurring in the last 50 years. This warming is primarily driven by greenhouse gas emissions from human activities.
- • Heat waves becoming more frequent and intense
- • Cold snaps becoming less frequent and less severe
- • Growing seasons lengthening in many regions
- • Polar ice melting at accelerated rates
- • Sea levels rising due to thermal expansion and ice melt