Bernhard - Interesting chart. I notice that egg production falls to 0 when the daytime high temp is at or below freezing and increases sharply starting at about 5 degrees Celsius (41 F) which seems about right just based on observation. I've never seen it quantified like that though. I assume that you feel that is accurate?
Aside from swarming issues this data should give some insight about what is going on it the hives in (our) winter and early spring when we often have several days (or weeks) with temps in the 40s followed by colder periods - possibly correlating to clusters getting stuck on brood and starving to death with honey only 3 inches away. Completely preventable if it can be predicted.
You don't by any chance have that as a working spreadsheet that you would let out?