Check the weather for your intended dates of travel. New York winters are cold, with blizzards probable in February. The summers are unbearably humid, leaving you ready for a second shower by lunchtime. Pack business attire appropriate for your line of work. Choose lighter weight materials for the summer months.
Women wear hose with suits despite the summer heat and tights for warmth in the winter.
Don't forget comfortable dressy casual clothes to blend into the New York scene. Men pair khakis or cords with a nice button-down shirt and leather loafer. Women pair a knee-length skirt and sweater set with a leather flat. Take a heavy winter coat, long underwear, sweaters, boots, socks, gloves, a scarf and a hat if you plan to be in New York between November and March. Wear rubber-soled shoes to avoid slipping on ice or snow.