On Aug. 11, "Autumn Tiger" is still showing its fierce manner, even though the Beginning of Autumn has gone. The temperature of the day has been up to 38 centigrade degree, the officials and soldiers of the border guard of the county came to Dongtou back beach and nearby hills, training tactical skills like arresting and manhunting, and exercising energy in the sun.

PS. "Autumn Tiger" , a slang of Chinese, means the especially hot weather after the Beginning of Autumn has gone.
Hi Jobb,

I think the 'autumn tiger' can be generally understood by any reasonably cosmopolitan non-Chinese. Here is my version, but it has a couple of uncertainties [in brackets]:

'On Aug. 11, the "Autumn Tiger" is still showing its ferocity, even though the beginning of autumn has passed. Today's temperature reached 38 degrees Celsius, and the officers and soldiers of the county ['country'?] border guard came to Dongtou back beach and the nearby hills to train under the hot sun in tactical skills like arresting and manhunting. '
The "Autumn Tiger" has fiercely pounced upon us this August 11, bringing temperatures up to thirty-eight degrees centigrade. The county's officals and soldiers who are tasked with guarding the borders have come to Dongtou beach and the nearby hills, taking advantage of the sunny days to practice manhunting and arrest skills.

I hope that helps. Since "Autumn Tiger" refers to the hot weather that occurs after the beginning of Autumn, I think it's redundant to say "even though the beginning of Autumn has gone..."

I hope it doesn't sound too much like a news report! Emotion: stick out tongue
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Are you native English speaker? Could you have got the "autumn tiger" at sight?
 Mister Micawber's reply was promoted to an answer.
exercise energy in the sun:

Exercise one's physical/body's energy while exposed to sunlight.
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Thanks Jobb, I just amended my original posting to reflect your explanation.