YOU SAID:

The cold days continued for three weeks.

INTO JAPANESE

寒い日が3週間続きました。

BACK INTO ENGLISH

The cold weather continued for three weeks.

INTO JAPANESE

寒い天気は3週間続きました。

BACK INTO ENGLISH

The cold weather lasted for three weeks.

INTO JAPANESE

寒い天気は3週間続いた。

BACK INTO ENGLISH

The cold weather lasted for three weeks.