Thanks for your company today and I hope we've provided a bit of light relief for keeping out of the oppressive record-breaking heat.
The bat has largely dominated ball, as we expected, and there have been six centurions on very good pitches.
But Ollie Hannon-Dalby's 6-40 for Warwickshire means he is the undoubted star of the day.
See you again tomorrow for day two.
Close of play scorecard
Division One:
Cheltenham: Gloucestershire v Hampshire 203-2
Northampton: Northants 218-7 v Lancashire
Taunton: Somerset 262-5 v Yorkshire
The Oval: Surrey 24-1 v Essex 271
Edgbaston: Warwickshire 155-6 v Kent 165
Division Two:
Derby: Derbyshire v Nottinghamshire 439-1
Lord's: Middlesex v Sussex 328-4
Close of play at Edgbaston
Warwickshire 155-6 v Kent 165
A solitary over of spin from Jack Leaning to end the day.
Sam Hain ends 68 not out as Warwickshire trail by just 10 runs on a fast moving day.
Still going at Edgbaston
Warwickshire 149-6 v Kent 165
Danny Briggs has offered some useful support to Sam Hain.
They have put on 24 for the seventh wicket and while not massive it has taken a bit of heat out of the game after Warwickshire slipped to 125-6.
Still four overs to go.
Close of play at Taunton
Somerset 262-5 v Yorkshire
And that's the end of day one at Somerset.
And what a fine day it was for skipper Tom Abell who goes to the close unbeaten on 114.
Yorkshire's five wickets have kept them in the game though.
Close of play at Lord's
Middlesex v Sussex 328-4
Goodness me, that was close. Cheteswar Pujara edges a snorter from fellow countryman Umesh Yadav just over the slips from the final ball of the day.
But it's Sussex's day at HQ, thanks to the hundreds of Tom Alsop and Pujara, but those two late wickets from Tom Helm will give Middlesex something to work with on day two.
WICKET Lenham c Robson b Helm 0
Middlesex v Sussex 318-4
Tom Helm has produced a big effort late in the day for Middlesex, striking twice in an over.
He has centurion Tom Alsop caught behind and then young Archie Lenham slashes one to second slip as he survives for just three balls.
Action-packed at Edgbaston
Warwickshire 139-6 v Kent 165
Warwickshire's decision to produce a pitch with more life for the bowlers has certainly worked.
We've had more than 300 runs and 16 wickets in an action-packed day at Edgbaston.
The sun has come back out and we may well get all the remaining 10 overs in.
WICKET Rew c Kohler-Cadmore b Bess 9
Somerset 246-5 v Yorkshire
Another Division One wicket falls late in the day.
This time Somerset teenager James Rew is caught at slip off spinner Dom Bess.
Three and a bit overs to go tonight at Taunton.
WICKET Burgess c Billings b Saini 0
Warwickshire 133-6 v Kent 165
An astonishing over from Navdeep Saini!
He bowls four successive no-balls but then he delivers a legitimate delivery which Michael Burgess edges behind.
Saini has the ridiculous figures of 8-1-55-3, with 12 no-balls!!
WICKET Patel c Harmer b S Cook 4
Surrey 24-1 v Essex 271
Essex strike just before the close!
Ryan Patel edges Sam Cook to slip and Simon Harmer takes a fine catch.
Big boost for the visitors as stumps is called at The Oval.
for Abell
Somerset 246-4 v Yorkshire
A captain's innings from Tom Abell!
The Somerset batter goes to his third hundred of the campaign off 198 balls with 12 fours and two sixes.
Excellent knock from the 28-year-old.
Close of play at Derby
Derbyshire v Nottinghamshire 439-1
A sensational day for Nottinghamshire and batters Ben Duckett and Haseeb Hameed.
Duckett ends on 237 not out and Hameed is on a career best 165. Their partnership is worth 393.
They need six more to notch up Notts' highest ever second wicket stand, beating a record that stands since 1890, while if they can score 13 more, it will be the highest stand for any wicket for the county.
Post update
Somerset 233-4 v Yorkshire
Tom Abell sweeps spinner Jack Shutt for six and follows it with a single to move to 99...
Post update
Surrey 20-0 v Essex 271
Couple of overs left in the day at The Oval.
Ryan Patel and Rory Burns faced with the challenge of seeing them off for Surrey.
WICKET Mousley c Billings b Saini 0
Warwickshire 125-5 v Kent 165
Dan Mousley has been and gone.
That should be left alone but he can't resist flashing at a wide one and Sam Billings takes the catch.
A second wicket on his Kent debut for Navdeep Saini in seven overs of liquorice allsorts.
WICKET Rhodes c Bell-Drummond 32
Warwickshire 122-4 v Kent 165
Will Rhodes has given it away late in the day.
Slightly over-pitched from Matt Milnes but Rhodes goes for a lazy drive with a lack of foot movement and he hits it straight to point.
That ends a stand of 90 and Kent will be relieved to have another wicket in the bag before stumps.
Murtagh and Middlesex under the pump
Middlesex v Sussex 302-2
Getty ImagesCopyright: Getty Images
Shades of Nasser Hussain in Brisbane for Tim Murtagh here. This was what you feared when he asked Sussex to bat this morning.
The Middlesex captain has watched Tom Alsop and Cheteswar Pujara bat and bat.
Both have reached hundreds and their stand is now worth 203 as the score has gone beyond 300.
for Haseeb Hameed
Derbyshire v Nottinghamshire 403-1
Haseeb Hameed is not quite keeping up with Ben Duckett, but this is a fine knock nonetheless.
He brings up a single to reach his 150 off 257 balls. Well played indeed.
A question for Derbyshire fans - which is worse: conceding 265 in a T20 match or seeing your team ship more than 400 runs in a single day of Championship cricket?
400 up for Notts
Derbyshire v Nottinghamshire 401-1
Yes, you have read that correctly.
Nottinghamshire have brought up the 400 on day one and secured the maximum five batting points.
Live Reporting
Adam Lanigan and Gary Smee
All times stated are UK
Getty ImagesCopyright: Getty Images 
Getty ImagesCopyright: Getty Images
Latest PostSee you tomorrow
Thanks for your company today and I hope we've provided a bit of light relief for keeping out of the oppressive record-breaking heat.
The bat has largely dominated ball, as we expected, and there have been six centurions on very good pitches.
But Ollie Hannon-Dalby's 6-40 for Warwickshire means he is the undoubted star of the day.
See you again tomorrow for day two.
Close of play scorecard
Division One:
Cheltenham: Gloucestershire v Hampshire 203-2
Northampton: Northants 218-7 v Lancashire
Taunton: Somerset 262-5 v Yorkshire
The Oval: Surrey 24-1 v Essex 271
Edgbaston: Warwickshire 155-6 v Kent 165
Division Two:
Derby: Derbyshire v Nottinghamshire 439-1
Lord's: Middlesex v Sussex 328-4
Close of play at Edgbaston
Warwickshire 155-6 v Kent 165
A solitary over of spin from Jack Leaning to end the day.
Sam Hain ends 68 not out as Warwickshire trail by just 10 runs on a fast moving day.
Still going at Edgbaston
Warwickshire 149-6 v Kent 165
Danny Briggs has offered some useful support to Sam Hain.
They have put on 24 for the seventh wicket and while not massive it has taken a bit of heat out of the game after Warwickshire slipped to 125-6.
Still four overs to go.
Close of play at Taunton
Somerset 262-5 v Yorkshire
And that's the end of day one at Somerset.
And what a fine day it was for skipper Tom Abell who goes to the close unbeaten on 114.
Yorkshire's five wickets have kept them in the game though.
Close of play at Lord's
Middlesex v Sussex 328-4
Goodness me, that was close. Cheteswar Pujara edges a snorter from fellow countryman Umesh Yadav just over the slips from the final ball of the day.
But it's Sussex's day at HQ, thanks to the hundreds of Tom Alsop and Pujara, but those two late wickets from Tom Helm will give Middlesex something to work with on day two.
WICKET Lenham c Robson b Helm 0
Middlesex v Sussex 318-4
Tom Helm has produced a big effort late in the day for Middlesex, striking twice in an over.
He has centurion Tom Alsop caught behind and then young Archie Lenham slashes one to second slip as he survives for just three balls.
Action-packed at Edgbaston
Warwickshire 139-6 v Kent 165
Warwickshire's decision to produce a pitch with more life for the bowlers has certainly worked.
We've had more than 300 runs and 16 wickets in an action-packed day at Edgbaston.
The sun has come back out and we may well get all the remaining 10 overs in.
WICKET Rew c Kohler-Cadmore b Bess 9
Somerset 246-5 v Yorkshire
Another Division One wicket falls late in the day.
This time Somerset teenager James Rew is caught at slip off spinner Dom Bess.
Three and a bit overs to go tonight at Taunton.
WICKET Burgess c Billings b Saini 0
Warwickshire 133-6 v Kent 165
An astonishing over from Navdeep Saini!
He bowls four successive no-balls but then he delivers a legitimate delivery which Michael Burgess edges behind.
Saini has the ridiculous figures of 8-1-55-3, with 12 no-balls!!
WICKET Patel c Harmer b S Cook 4
Surrey 24-1 v Essex 271
Essex strike just before the close!
Ryan Patel edges Sam Cook to slip and Simon Harmer takes a fine catch.
Big boost for the visitors as stumps is called at The Oval.
for Abell
Somerset 246-4 v Yorkshire
A captain's innings from Tom Abell!
The Somerset batter goes to his third hundred of the campaign off 198 balls with 12 fours and two sixes.
Excellent knock from the 28-year-old.
Close of play at Derby
Derbyshire v Nottinghamshire 439-1
A sensational day for Nottinghamshire and batters Ben Duckett and Haseeb Hameed.
Duckett ends on 237 not out and Hameed is on a career best 165. Their partnership is worth 393.
They need six more to notch up Notts' highest ever second wicket stand, beating a record that stands since 1890, while if they can score 13 more, it will be the highest stand for any wicket for the county.
Post update
Somerset 233-4 v Yorkshire
Tom Abell sweeps spinner Jack Shutt for six and follows it with a single to move to 99...
Post update
Surrey 20-0 v Essex 271
Couple of overs left in the day at The Oval.
Ryan Patel and Rory Burns faced with the challenge of seeing them off for Surrey.
WICKET Mousley c Billings b Saini 0
Warwickshire 125-5 v Kent 165
Dan Mousley has been and gone.
That should be left alone but he can't resist flashing at a wide one and Sam Billings takes the catch.
A second wicket on his Kent debut for Navdeep Saini in seven overs of liquorice allsorts.
WICKET Rhodes c Bell-Drummond 32
Warwickshire 122-4 v Kent 165
Will Rhodes has given it away late in the day.
Slightly over-pitched from Matt Milnes but Rhodes goes for a lazy drive with a lack of foot movement and he hits it straight to point.
That ends a stand of 90 and Kent will be relieved to have another wicket in the bag before stumps.
Murtagh and Middlesex under the pump
Middlesex v Sussex 302-2
Shades of Nasser Hussain in Brisbane for Tim Murtagh here. This was what you feared when he asked Sussex to bat this morning.
The Middlesex captain has watched Tom Alsop and Cheteswar Pujara bat and bat.
Both have reached hundreds and their stand is now worth 203 as the score has gone beyond 300.
for Haseeb Hameed
Derbyshire v Nottinghamshire 403-1
Haseeb Hameed is not quite keeping up with Ben Duckett, but this is a fine knock nonetheless.
He brings up a single to reach his 150 off 257 balls. Well played indeed.
A question for Derbyshire fans - which is worse: conceding 265 in a T20 match or seeing your team ship more than 400 runs in a single day of Championship cricket?
400 up for Notts
Derbyshire v Nottinghamshire 401-1
Yes, you have read that correctly.
Nottinghamshire have brought up the 400 on day one and secured the maximum five batting points.
Ben Duckett motoring along on 217 not out.