I go crazy trying to keep straight what kinds of "average" people mean when they talk about weather statistics.
For example, someone printed that these were "means".
mean max 19C
mean min 8.4C
Does that mean that the AVERAGE daily low in some season is 8.4C?
(Collect the daily low for every night in some season, then average those?)
Like "an AVERAGE winter night has a low temp of 19C"
Your collection of stats starts out by saying "Long-term Averages". That makes them unsuitable for figuring the USDA Hardiness (your stats are much more generally informative than USDA Hardiness !
The USDA "Hardiness" stat is different (and has only limited usefulness). It looks at the very coldest temperature reached in one whole year. The extreme temp reached, not an average of several lowest DAILY temperatures.
After accumulating those "very lowest temp of the year" for 20 or more years, they count the number of years where the temp ever went below "X". Then they try different "X"s until half of the last 20 years DID go below X and half did not.
That's all the USDA Hardiness Zones mean: if a low temp of "X" will kill your plant, expect half of all winters to kill that plant. Not very informative for annual crops, is it?
It's wildly unlike a description of a climate. For example, parts of Texas are Zone 8b but their summer heat kills most of their tomato crop off before my weather gets mild enough to even transplant tomato seedlings outdoors (Coastal Pacific Northwest maritime climate, cool-Mediteranian). Koppen Zone Csb.
