The third day of Formula 1 pre-season testing has been delayed after the forecast snow hit the Circuit de Barcelona-Catalunya overnight and continued to fall through the morning.

Teams were left frustrated by cold conditions on Monday afternoon and Tuesday morning that made running troublesome, but worse was to come as snow fell through the night and began to lay at the track.

While circuit officials worked to keep the tarmac itself as clear as possible, snow is continuing to fall at the track, with race control confirming that the session would be red flagged until the medical helicopter was able to fly.

The snow is expected to continue until about 11 a.m. before turning into rain that will persist throughout the day with a highest temperature of 8ºC. The temperature gauges record both the air and track temperature as being exactly 0ºC.

"There is no point going out there," Haas F1 team boss Günther Steiner said of the cold conditions late on Tuesday before the snow arrived.

"You don’t learn anything, we would never run in these circumstance and the only thing you do is risk the cars, and being the first test of the season, we are lean on spares and we cannot risk it.

"At the moment it doesn’t look much better on Thursday. It’s getting warmer, but still wet."

Teams did discuss potentially cancelling Wednesday's session and holding a day of testing on either Friday or Monday instead, but the required unanimous backing was not achieved.