Floods and torrential rain have been blamed by two of the country's main rail operators for disappointing punctuality figures.
East Coast managed to run 84.9% of its services on time while Virgin Trains' figures were 86.5% for the period June 24 to July 21.
There was better news for passengers of c2c services - between South Essex and London Fenchurch Street - which has set a new punctuality record for the last year, with a score of 97.1%. Nationally, 92.7% of trains hit their punctuality target, up slightly from last year's figure of 92.2% for the same period.
Commuter trains must arrive within five minutes and long distance services within 10 minutes to count as being on time. Trains cancelled due to external factors, such as the weather, vandalism or suicides still count against operators' scores.
An East Coast spokesman said: "The unprecedented wet weather, which caused severe flooding and landslips at the end of the wettest June on record, was responsible for two out of the three incidents which caused the most delay to East Coast services.
"Our moving annual target, which indicates the longer term improvements we have been making, continues to rise ahead of target."
Steven Knight of Virgin Trains said: "We are disappointed but we did have the severe weather we experienced with torrential rain and landslips."
National Express runs the c2c service, which includes the Olympic venue stations of West Ham and Leigh-on-Sea, the host of mountain biking next week.
Managing director Julian Drury said: "c2c is now taking thousands of passengers to the Games every day on a record-breaking train service. We're continuing to set the pace for train companies in the UK, and I'm proud c2c is consistently finishing top of the podium."
The Association of Train Operating Companies said members were not complacent. A spokesman said: "Punctuality has improved significantly over recent years as the industry has worked together to get more trains arriving on time. We're not complacent and will continue to focus on providing passengers with the service they expect and deserve."