Oscar Piastri admitted he struggled for pace in his McLaren in warmer conditions during Qualifying for the Miami Grand Prix.

Piastri qualified 19th for Sunday’s race with a time just 0.159s away from that which would have seen him progress to Qualifying 2.

He was within a tenth of team-mate Lando Norris, who will line up 16th, in a disappointing session for McLaren.

“It’s been a difficult day,” Piastri told media, including Speedcafe.

“At the beginning of the session, I was a bit surprised that the track wasn’t quick compared to the end of Free Practice 3 – then it obviously improved quite a bit through the session.

“Regardless of track evolution, I think we were struggling for pace throughout the whole session today.

“It’s super, super close. It’s been the same story the whole year – we’re at risk of going out in Q1 every weekend but also where we have the chance to be in Q3 every weekend.

“Today we’re just at the back end of that bracket, unfortunately. It’s been a tough day.”

McLaren had shown promising pace on Friday in Miami, only for that to disappear on Saturday.

That was despite conditions remaining essentially unchanged; both days saw the mercury hit 31.

When cars hit the track for qualifying, temperatures hovered at 29 degrees, as they had been at the start of Free Practice 3 yesterday.

By contrast, temperatures in Azerbaijan were 21 degrees at the start of Friday’s qualifying session, which saw both McLarens inside the top 10.

“We’re struggling a bit with these hotter conditions,” Piastri said when asked by Speedcafe where the car was lacking.

“In general, it’s not sort of one place where we’re struggling massively; it’s just little bits everywhere.

“P2 yesterday looked more encouraging; maybe our fuel load or engine mode was maybe a bit better than others at that point.

“But it was also the coldest track conditions and we looked more competitive as well.

“So I think we need to understand why we struggle a bit more when it’s hotter.

“The temperature is obviously massively different to Baku,” he added.

“I think the type or tarmac is also a bit different as well; the layout is very different.

“So there’s quite a lot of differences to Baku; a lot of longer corners here.

“All of those factors are probably contributing to the pace this weekend.”

Sunday’s race will be held in cooler conditions, with temperatures slightly lower than seen across the weekend.

A chance of rain also exists, though while that was predicted to spike as the grand prix started, any precipitation is now forecast to fall in the morning.

The Miami Grand Prix begins at 15:30 local time on Sunday (05:30 AEST Monday).