Even though it had been snowing all day, a great many people managed to get to the end-of-term concert.

Very few people indeed were prevented from getting to the end-of-term concert by the heavy snow.

Since there had been snow all day long it wasn't easy for people to get to the end-of-term concert.

As it had been snowing heavily all day, a great many people just could not get to the end-of-term concert.

A lot of people did get to the end-of-term concert in spite of the snow that fell all day.