This map was created by Andreas Bärtels in 2001, using data provided in an article on gardening by Dr Shreiber. The map, which appeared in the Enzyklopädie der Gartengehölze, shows the average minimum temperature recorded in Europe throughout the winter.

For visualisation purposes, the map groups the different areas into eleven temperature ranges:

• 11 (dark red): over 4.4°C
• 10: between -1.2°C and 4.4°C
• 9 (orange): between -6.7°C and -1.2°C
• 8: between -12.3°C and -6.7°C
• 7 (yellow): between -17.8°C and -12.3°C
• 6: between -23.9°C and -17.8°C
• 5: between -28.9°C and -23.9°C
• 4 (green): between -34.5°C and -28.9°C
• 3: between -40.0°C and -34.5°C
• 2: between -45.5°C and -40.0°C
• 1 (white): below -45.5°C

Sources

• Baja temperatura invernal en Europa