HOBOKEN, NJ — Whenever fireworks explode over the Hudson River, residents on both the New York City andNew Jersey side wonder about the occasion.

Some are irked because pets can get spooked and run away, and babies wake up. And when they come around the 9/11 anniversary, folks are sometimes even more unnerved.

If you’re hearing fireworks on Sept. 7, which is a Sunday, here’s why.

The fireworks were postponed from Saturday due to the weather.

Around 4:20 p.m. in Hoboken, some fireworks could be heard — likely testing in advance of a display slated for Sunday night.

Hoboken’s 99th annual Italian Festival, otherwise known as the Feast of the Madonna dei Martieri, began on Thursday and runs through Sunday. Fireworks were planned for the city’s waterfront around 9:15 Sunday (postponed from Saturday).

The tradition of the Madonna Dei Martiri festvial goes back to the year 1399, when the King of Napoli, Ladislao di Durazzo, ordered that a street festival and religious celebration be combined to celebrate the “Miracle” and blessings of the Madonna.