Nairobi, Kiambu and Nakuru had the highest increases in the number of registered voters between 2013 and 2017.
The three counties recorded a combined fifth of the 5.2 million new voters nationally.
However, the final voters roll retains the more than 1.5 million voters estimated to have died from 2013 to date by a KPMG audit.
Nearly 90,000 voters confirmed to have died were removed from the register. However, the Independent Electoral and Boundaries Commission had no way of verifying the actual number and identities of those estimated to have died who might still be on the register.
KPMG had based its findings on population and registrar of deaths data to conclude that 1.5 million people over the age of 18 have died between 2012 and December last year, when the current register was developed.
The audit confirmed by name and national identity card number 92,277 dead voters still on the roll but the number was corrected to 88,602, who were expunged from the register.
The rest could not be traced as there was no system linking the IEBC and the Registrar of Deaths databases.
However, the IEBC argues that that is not a major problem as there was no risk of the dead waking up to vote.
“We are aware that the register of voters cannot be completely rid of deceased persons,” said IEBC chairman Wafula Chebukati this week as he released the new figures. “However, we are confident that the KIEMS technology provides foolproof authentication on Election Day and there will be no room for mischief.”
The county with the highest voter increase is Nairobi with 518,565 to top the country with a 2,250,853 total.
Next is Kiambu with 317,721 new voters for a total of 1,180,920, followed by Nakuru with 253,024 new listings to bring the county’s total to 949,618.
An analysis of the official tally of registered voters nationally on the final roll published by the IEBC shows that the number increased by 5,222,642 from 2013.
The increase from 14,388,781 to 19,611,423 voters represents a 36 per cent bulge.
It is this new crop of voters that could be the make-or-break factor at the August 8 presidential election rematch between President Uhuru Kenyatta and the opposition’s Raila Odinga.
In the 2013 elections, President Kenyatta triumphed with a margin of 833,887, which was just some 8,000 votes above the 50 per cent-plus-one votes that he needed to clinch an absolute majority and avoid a run-off.
The other counties with major increases in the number of registered voters are Meru, by 212,890 to hit 702,480, while Kakamega increased by 175,585 to hit 743,736, Machakos listed 174,833 new voters for a 620,254 total and Kilifi got a 171,658 increase to hit 508,068.
Other leading counties are Mombasa at 580,223, having increased by 167,154, Kisumu added 152,604 to take the total to 539,210 and Homa Bay numbers increased by 150,370 to reach 476,875.
Kitui rounds off the top 10 with a 149,714 increase to reach 474,512 voters.
But it is the 51 per cent of Kenyan youth aged 18 to 35 numbering 9,930,315 in the register that could be the decider.
The former Rift Valley Province, comprising 14 counties, has 4,649,768 – the single biggest unit with the most votes.
Ranked between 10 and 20 in the list of the highest increases are Bungoma, Siaya, Kisii, Murang’a, Makueni, Uasin Gishu, Kwale, Migori, Kajiado, Nyeri and Busia.
Those that saw the smallest increase were Lamu, Isiolo, Samburu, Marsabit, Tana River, Taita-Taveta, Wajir, Elgeyo-Marakwet, Garissa, Mandera and Turkana.
In percentage terms, the Coast counties of Kwale, Kilifi and Tana River topped the list of those with the highest percentage increase in the number of voters in 2017 from those that were in the roll in 2013.
The counties managed 60.07, 51.03 and 48.58 per cent increases, respectively, with West Pokot coming in between them at 48.70 per cent.
Siaya, Kitui, Homa Bay, Mandera, Meru, Turkana, Makueni, Garissa and Laikipia had between 46 per cent and 41 per cent increase in the number of voters.