"L'été dernier" or "en été dernier"?

Question

"I went to France last summer."

Should this be translated as

Je suis allé en France l'été dernier.

or

Je suis allé en France en été dernier.

? I know that "in summer" is usually translated with "en été", but when there's a modifying adjective I'm not sure which is the correct translation.

Answer 1

As said before :

Je suis allé en France l'été dernier.

You give a precise time indication : last year's summertime.

Some variations to answer better your concern :

• "Je suis allé en France en été." : means "during the summer season". You indicate the season only.
• "Je suis allé en France en été dernier." : this form is not used
• "Je suis allé en France en été l'an dernier." : is a possible combination. It indicates the same time as the chosen answer, but it is used to answer the question "Which year did you go to France in summertime?"

Answer 2

Je suis allé en France l'été dernier