Karnataka, a state in southern India, exhibits diverse climatic conditions due to its varied topography and geographical location. The state is divided into distinct climatic regions, each with its unique weather patterns and environmental characteristics. The state Gazetteer has classified Karnataka into four climatic regions, and according to Köppen's classification, it is further divided into three climatic divisions. Here’s an overview of these classifications:

State Gazetteer Classification:

1. Coastal Region:

• Location: This region lies to the west of the Western Ghats.
• Rainfall: The area receives more than 300 cm of annual rainfall.
• Climate: The coastal region experiences a tropical monsoon climate with heavy rainfall, especially during the southwest monsoon season (June to September).
• Vegetation: Dense tropical evergreen forests dominate this area due to the high rainfall.
• Temperature: The region has moderate temperatures throughout the year, with slight variations between summer and winter.

2. The Western Ghat Region:

• Location: Extends from Belagavi in the north to the southwestern part of Mysuru district.
• Rainfall: Annual mean rainfall ranges from 400 to 800 cm, decreasing eastwards up to an isohyet of 200 cm.
• Climate: Known for its heavy monsoon rains and lush green landscapes, the Western Ghats act as a significant barrier for the monsoon winds, causing heavy rainfall on the windward side.
• Vegetation: The region is characterized by tropical rainforests and deciduous forests.
• Temperature: The Western Ghat region has a cooler climate compared to the coastal area, with temperatures varying with elevation.

3. Northern Plain Region:

• Location: Covers the entire northern maidan region of the state.
• Elevation: Mean elevation is about 350 to 650 meters.
• Rainfall: Mean annual rainfall is between 50 to 150 cm.
• Climate: This region has a semi-arid climate with relatively low rainfall. It experiences hot summers and mild winters.
• Vegetation: The vegetation is predominantly dry deciduous forests and scrublands.
• Temperature: Summers can be quite hot, while winters are cooler and more pleasant.

4. Southern Maidan Region:

• Location: Characterized by undulating topography, extending to elevations ranging between 600 to 1000 meters.
• Rainfall: Annual mean rainfall varies from 46 to 200 cm.
• Climate: This region experiences a tropical savanna climate with distinct wet and dry seasons.
• Vegetation: The vegetation includes dry deciduous forests and grasslands.
• Temperature: The area has moderate temperatures, with cooler conditions in higher elevations.

Köppen’s Climatic Classification:

1. Amw: Tropical Monsoon Region

• Location: Includes the coastal plains and the Western Ghats.
• Climate: Characterized by dry winters and very wet summers. The monsoon season brings heavy rainfall, while the dry season sees significantly reduced precipitation.
• Vegetation: Lush tropical rainforests and dense vegetation.

1. Bshw: Semi-Arid Steppe Type Climate

• Location: Covers the entire northern part of the state.
• Climate: The largest climatic region of Karnataka, featuring semi-arid conditions with low annual rainfall. This area experiences hot and dry conditions for most of the year.
• Vegetation: Sparse vegetation, mainly consisting of grasslands and thorny bushes.
• Temperature: High temperatures during summer and moderate winters.

iii. Aw: Tropical Savanna Climate

• Location: Encompasses the entire southern and southeastern part of the state.
• Climate: Marked by a clear distinction between the wet and dry seasons. The region receives moderate rainfall during the monsoon season, while the rest of the year remains relatively dry.
• Vegetation: Mixed vegetation including grasslands and scattered trees.
• Temperature: Moderate to high temperatures throughout the year, with a noticeable drop during the winter months.

Summary:

Karnataka's climate is influenced by its geographic features, including the Western Ghats, coastal plains, and varying elevations across the state. The diverse climatic regions impact the state's agriculture, vegetation, and overall lifestyle of the inhabitants. Understanding these climatic zones is crucial for effective resource management and sustainable development in the state.