California Wine Growing Climate

Question 1

Summarise California’s climate.

Answer 1

Mediterranean. Hot sunny summers, mild winters with low rainfall.
Cold Humboldt current bringing cool breezes and fog as inland temperatures rise.
Cool nights and mornings are good for acidity and long hang time.
The cool coast and warm interior is most important.

Question 2

Risks to vines in California’s climate.

Answer 2

Seasonally, Spring frost.

Generally, Global warming problems (temp, floods, fires)

Question 3

Explain the five degree days scale for winegrowing.

Answer 3

Prof. Winkler of UC Davis.
Classified California’s wine regions on a scale of “degree days”.
It measures the time the temperature is over 10°C between 1 April and 31 October.
Region 1, very cool. Region 5, very hot.
Intended to assist growers to know which grape varietals are best suited.

Question 4

Explain the shortfall of the “degree days” system.

Answer 4

It reflects average temperatures.
Ignores rainfall patterns and other differences.
Areas with extreme differences in 24h temperatures can have a similar average as a region with small 24h range temperature difference.