Couldn`t tell you anything about what they need to come out.
I can only speak for my area`s in south Bavaria, they are one of the latest Herps that come.
I rarely see them before End of March, but in the most years the came out in the first weeks of April.
And if they are out, they are out. That means I found them out during rain, no sun and Temperatures around 10 Degrees in the End of April one year.
And the Adults disppear end of August. beginning of September doesn`t matter what Temperatures we have.
the hatchlings disappear middle of October, beginning of November.
Very different to the area of Michael Glass around Nurnberg, I think they are out year around there!
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