South of France here (5°C - 35°C outside, 15°C - 30°C inside my flat), I don't use any heating nor hot water, nor air conditioning all year long, very few devices and really low electricity bill (10€/mo)
I have to pay about double that per month (in £) for electricity, even if I don't use any electricity at all! And the electricity I do use costs nearly that much per day, and that's without having to use any of it for heating or hot water, which is all on gas and costs about as much again.
I don't have heating nor hot water as said, it's basically light, laptop, rice cooker, fan in summer sometimes (hence +1€ there)
You probably have leaks or plugged devices