Average Water Temperatures: Freshwater and Saltwater Ranges Worldwide

Freshwater

• Arctic lakes and rivers: 32–41 °F (0–5 °C)
• Temperate lakes and rivers: 46–68 °F (8–20 °C)
• Tropical lakes and rivers: 68–95 °F (20–35 °C)

Saltwater

• Polar oceans: 28–32 °F (−2 to 0 °C)
• Temperate oceans: 41–59 °F (5–15 °C)
• Tropical oceans: 77–86 °F (25–30 °C)

The average global ocean temperature is about 59 °F (15 °C).