However the conditions in the UK are so unpredictable , and being temperate it is easy to underestimate the enviroment. Choice of clothing is made harder, too much and you sweat, too little and you can get cold.
The sun has a reasonable amount of power in June, thankfully, because the animals need it. The young , especially those that live under ground will be getting soaked, and risk dying from getting wet and then cold.
I am always amazed by survival tricks used by animals to cope with their environment, and especially the humble wildlife in the UK, they are having a tough time. The woods are quiet at the moment, I think the wildlife is still recovering from an un-seasonal lashing, but I expect once they venture out