The final race of the Silverstone weekend starts at 15.55, with Double R's Neil Verhagen on pole position.
The grid for race three is decided by each driver's second best times from qualifying, with Verhagen's second best time of 2m17.180s from the wet qualifying session being 0.232s quicker than race one winner and championship leader Clement Novalak.
Chris Dittmann Racing's Ayrton Simmons and Fortec's Johnathan Hoggard will line-up on row two, with Hampus Ericsson and Kaylen Frederick starting fifth and sixth.
Hillspeed's Sasakorn Chaimongkol and Fortec's Manuel Maldonado will start from row four while Carlin's Lucas Petersson and Douglas Motorsport's Kiern Jewiss will complete the top-10.
Series newcomer Nico Varrone starts 11th for Hillspeed ahead of race two winner Benjamin Pedersen.
Meanwhile, Kris Wright had been due to start 17th, but has been handed a penalty by the Clerk of the Course for the incident with Kiern Jewiss in race two. The Clerk of the Course decision states that Wright left the track and when coming back on track made contact with Jewiss. Wright therefore has a five place grid penalty, but will instead start from 18th and last, and picks up three penalty points also.
The full race three grid is shown below. The race can be followed with live timing and streaming by clicking here.
BRDC British F3 Championship, Silverstone race three grid:
1. Neil Verhagen, Double R Racing
2. Clement Novalak, Carlin
3. Ayrton Simmons, Chris Dittmann Racing
4. Johnathan Hoggard, Fortec Motorsports
5. Hampus Ericsson, Double R Racing
6. Kaylen Frederick, Carlin
7. Sasakorn Chaimongkol, Hillspeed
8. Manuel Maldonado, Fortec Motorsports
9. Lucas Petersson, Carlin
10. Kiern Jewiss, Douglas Motorsport
11. Nico Varrone, Hillspeed
12. Benjamin Pedersen, Douglas Motorsport
13. Nazim Azman, Chris Dittmann Racing
14. Andreas Estner, Lanan Racing
15. Ulysse De Pauw, Douglas Motorsport
16. Pavan Ravishankar, Double R Racing
17. Josh Mason, Lanan Racing
18. Kris Wright, Fortec Motorsports
18 August 2019 - Simmons soars to Silverstone race three triumph
18 August 2019 - What they said: Silverstone race three
18 August 2019 - Race three starts at 15.10 - Jewiss on pole
18 August 2019 - Maldonado splashes to victory in Silverstone race two
18 August 2019 - What they said: Silverstone race two