BRUSSELS • One thing Formula One teams cannot prepare for in the lead-up to this weekend's Belgian Grand Prix is the weather.

Haas driver Romain Grosjean believes it will, as usual, be unpredictable and play a crucial role in deciding the winner.

The sport returns from the summer break with practice sessions scheduled for Friday, but rain is expected at the Spa-Francorchamps circuit during the course of the three-day Grand Prix.

The Walloon region, where the race track is located, often has rain just minutes after blue skies and it is a problem the teams must counter.

But Grosjean told PlanetF1.com that it is something that no one can prepare for.

"Basically, you don't do anything about it," he said when asked how teams can prepare for the weather. "It's something that's out of your control. You don't really worry about it.

"When it comes to qualifying or race day, yes, you have to make decisions, but it's never black or white at Spa."

Last season, the 30-year-old, in a Lotus car, surprised many by qualifying fourth on a dry track and followed that up with third place in the 44-lap race.

"We had a good car last year," he said. "I had qualified fourth, but started ninth due to a gearbox penalty.

"We had a good strategy and good timing with the safety car, too. I managed to overtake a few cars and get on the podium."

This year, having swapped Lotus for Haas, Grosjean is looking to repeat that feat or do better at the Spa circuit.

"It's a great track," he said. "There are very high-speed corners and there are a lot of turns, different types, some high speed, some low - just a good variety overall.

"It gives you a good feeling to drive. You always see different approaches at Spa. Either you're fast in sector one and sector three, which are the high-speed sectors, or you're fast in sector two, which has more of the corners.

"Both work pretty well, so it's a matter of how you want to approach the race."

Red Bull's Daniel Ricciardo is also looking forward to racing at Spa-Francorchamps this weekend, especially after he won there in 2014.

The Australian driver had taken advantage of Mercedes rivals Lewis Hamilton and Nico Rosberg colliding early in the race to secure his third win of the season.

"Spa is cool and the track is amazing," the 27-year-old said. "It's very historic, fast and flowing. I had a win there two years ago so it has always been a good track to return to for me.

"I think it's funny how spread out the circuit is, on one side you can have sun while it rains on the other.

"I had a really good weekend there last year so hopefully we can have an even better result this year."

Ricciardo was on course for a strong result last year until he had to retire with a mechanical problem.