You absolutely can leave your russian outside. I'm in Sonoma County, and all mine (including yearlings) are outside from March - October. Night temps in the summers here are rarely above the mid-50s, often in the 40s. I have a dog house for them to sleep in, but they don't always use it.
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Sohni
2.2.2 Testudo horsfieldii
0.0.2 Testudo hermannii boetgeri
0.0.2 Testudo hermannii hermannii
1.0.0 Testudo marginata


