Simferopol has a continental climate sheltered from the sea by the Crimean Mountains. Summers (June–August) are hot and dry — usually a few degrees warmer than the southern coast at Yalta — and the city can feel airless and dusty in July and August.
The best months to visit are May, June, and September: warm but not stifling, with long days and the surrounding hills at their greenest. Winter (December–February) is cold and grey, with occasional snow; many seaside-focused tourist routes scale back or close, but the city itself stays busy.
For travellers using Simferopol mainly as a transit point, weather matters less than schedule — but be aware that the political situation since 2014 has dramatically changed connections, and visiting Crimea is restricted under Ukrainian law and difficult under most travel insurance policies.