UK Inflation Jumps to 3.5% - and West Kent's Own Pump Prices Show Exactly Why

The Office for National Statistics published its inflation figures for September 2026 today, and the headline number moved more than it has in a while: the Consumer Prices Index (CPI) rose 3.5% in the year to September, up from 3.1% in August. The more comprehensive CPIH measure, which also covers owner-occupier housing costs, rose to 3.6% from 3.3%.

The ONS was unambiguous about the cause: transport, "particularly motor fuels," made the single largest upward contribution to the change in both measures. The average UK petrol price rose 8.2 pence per litre between August and September, to 169.5p - the highest recorded since August 2022. Diesel rose even more, up 10.7p to 192.5p a litre, its highest since July 2022. Taken together, motor fuel prices are now 29.8% higher than a year ago, more than double the 23.0% annual rise recorded just the month before. Housing costs were the other big mover, with owner-occupiers' housing costs up 4.0% on the year - but fuel was the sharper, faster-moving change.

We've been tracking the cheapest advertised petrol and diesel price in each of our four boroughs daily since 17 September, and the same pattern shows up locally, even allowing that our window doesn't line up exactly with the ONS's August-to-September comparison. In every borough, diesel moved more than petrol over the five weeks to 21 October - exactly the imbalance the ONS is describing nationally.

Our own West Kent tracking only goes back five weeks, because that's when we started pulling the daily Fuel Finder data ourselves - Fuel Finder itself only ever publishes a live snapshot, not a history. But the Government also publishes a separate, much longer series: weekly average UK pump prices going back to 2018, via the Department for Energy Security and Net Zero. That one shows just how far this year's rise really stretches. The cheapest week of 2026 was the week of 9 February, when the national average stood at 131.5p for petrol and 140.7p for diesel. Prices barely moved for the first six weeks of the year, then climbed steeply from early March, spiked hard through April, eased back a little over the summer, and have been climbing again since August. By last week, the national average had reached 174.6p for petrol and 199.3p for diesel - up 43.1p (32.8%) and 58.6p (41.7%) respectively since that February low.

None of this is enough on its own to say West Kent is driving the national rate - the real question now is whether this keeps going, or whether September turns out to be the peak. Source: Office for National Statistics; local fuel price tracking is our own, compiled daily from the Government's Fuel Finder open data scheme; national weekly series from the Department for Energy Security and Net Zero.