Climate and Weather in Canada Notes

Surface Air Temperature Climatology

  • Observations from January-February-March (1963-1993) by Environment Canada
  • Significant temperature readings recorded in various cities (e.g., Lytton reached 49.6°C)
  • Temperature variation across Canada and north-west US

Weather vs Climate

  • Weather: Short-term atmospheric conditions (minutes to days). Includes:
  • Temperature, humidity, precipitation, wind speeds
  • Climate: Long-term weather patterns (decades), influencing daily life.
  • Weather: Day-to-day variations
  • Climate: Consistent patterns over time

Canada’s Climate

  • Variations in climate due to:
  1. Latitude:
    • Northernmost point: Alert (83°N); avg. temp -18.1°C
    • Southernmost point: Pelee Island (41°N); warmer temperatures
  2. Elevation:
    • Higher elevations = lower temperatures:
    • Air expands as it rises, leading to cooling due to lower pressure
  3. Coast vs. Inland:
    • Coastal regions have different climates than inland regions due to proximity to large water bodies
  4. Weather Systems Movement:
    • Wind and pressure systems transport weather across the country

Relief and Elevation

  • Relief: Differences in elevation influencing weather and climate
  • Mountain ranges obstruct air masses
  • Temperature decreases with elevation despite proximity to the sun

Continental vs. Maritime Climate

  • Continental Climate:
  • Found far from oceans
  • Greater seasonal temperature variations (hot summers, cold winters)
  • Maritime Climate:
  • Coastal areas experience smaller temperature range but higher precipitation due to moderating effects of water

Moderating Effect of Water

  • Large bodies of water heat and cool more slowly than land
  • Summer warmth of land cooling influenced by nearby cooler water bodies
  • Winter warmth retained by water moderating land temperatures

Ocean Currents

  • Influence air and water temperatures:
  • West Coast: Warm currents (North Pacific Current)
  • East Coast: Cool currents (Labrador Current)
  • Result: Milder winters in BC compared to Eastern Canada

Air Masses

  • Large volumes of air with specific characteristics:
  • Maritime Air: Contains moisture, leading to precipitation
  • Continental Air: Usually dry due to distance from bodies of water

Winds and Pressure Systems

  • Air Pressure: The weight of air creates pressure differences leading to wind
  • Warm air rises, creating low pressure; cold air sinks, creating high pressure
  • Prevailing Winds:
  • In Canada, mainly from west to east (westerlies) affecting local weather patterns
  • Different air masses (e.g., Arctic cold vs. Gulf of Mexico warmth) impact weather across regions

Polar Jet Stream

  • Fast-moving air current at high altitudes influencing weather patterns
  • Moves south in winter, bringing cold air southward
  • Moves north in summer, bringing warm air from the Gulf of Mexico