It's been a while since I went outside so the wind was chilly.
久しぶりに = been a while since 〇〇
外へ出る = go outside
冷たい = cold, chilly, freezing
久しぶりという挨拶は「Long time no see.」に訳せます。実は元々の文章は「It's been a while since I've seen you」です。そんな訳で、「久しぶりに〇〇」は「It's been a while since 〇〇」です。冷たいは色んな英単語があります。その三つの中では「freezing」は一番冷たいときに使います。
The wind was cold as I went outside after a long absence
「久しぶりに外へ出たら風が冷たかった」＝ The wind was cold as I went outside after a long absence.
「久しぶりに」= after a long absence; after a long while
「外へ出たら」= as I went out
「風が冷たかった」= the wind was cold
→
「会社に書類を送るため、久しぶりに外へ出たら風が冷たかった」= The wind was cold when I went outside for the first time in a while to send documents to the company.
「会社に書類を送るため」= (in order) to send documents to the company
になります。
ご参考までに。
アメリカ合衆国 
