How to determine best months for Products

[p45cal]

An update to include numbers and more:
The pivot now contains actual numbers of days as well as percentages.
There's a new table which allows you to create 'Products' with Max and Min temperatures (at cell AE2). This works by assigning 'Bad' to those days where the temperature is less than or equal to the Min OR the temperature is greater than or equal to the Max. [You can see this step in the Added Custom1 step of the ProductsEffectiveness query where the code is
if [Min] <= [Min.1] or [Max] >= [Max.1] then "Bad" else "OK"
this can be tweaked if necessary to handle missing data]
You can get days where say, the min is less than or equal to 10°C by putting 10 in the Min column, and a temperature that will always pass in the Max column eg. 100 (so all rows will be below 100). If you change any values in this table you'll need to refresh the pivot table (when the new 'Products' will appear in the Product slicer). After that you won't need to refresh again when choosing items in the slicers…

…talking of which, you can choose any combination of Products and Years using the mouse in the slicers with a combination the Ctrl or Shift keys.

There's a copy of the data converted to a table at cell AA1 which is easily pivot-able. This just for your information and isn't used and can be deleted - it's just a copy; the pivot table is fed from separate Power Query query in the background.

My results agree with Paul's largely; just out of interest, you say:

Year Month Your Results Physical check
2002 Nov 9 10

for values >=29.5°C

I get 9 too, made up of dates:
01/11/2002
03/11/2002
04/11/2002
09/11/2002
10/11/2002
13/11/2002
26/11/2002
27/11/2002
30/11/2002
2025-03-26_155333.jpg
being cells W71,W73,W74,W79,W80,W83,W96,W97,W100 (highlighted with red font in the attached).
Which is the extra cell you're counting to get 10?