The M25 from the air (Mike McBey, CC BY 2.0, via Wikimedia Commons — file photograph, not this weekend’s works).
Drivers heading to Heathrow have won a week’s reprieve. The planned overnight closure of the M25 at junction 15 — due to shut the anticlockwise carriageway from 8pm tonight — has been postponed because of forecast bad weather, National Highways and its contractor Connect Plus have confirmed.
The anticlockwise carriageway at junction 15, between the M4 slip roads, will now close from 8pm on Saturday 31 October until 10am on Sunday 1 November 2026 instead. The clockwise carriageway and every link between the M25 and the M4 will stay open throughout the works.
In a letter to nearby residents this morning, Connect Plus said the forecast adverse weather meant this weekend’s closure could not go ahead safely. Contingency closures are routine for this kind of work — but they still catch drivers out, which is why the one-week delay matters for anyone who had already planned their airport run around tonight’s works.
The official diversion route
When the closure takes place next weekend, M25 anticlockwise traffic will need to exit at junction 15. A fully signed diversion will be in place to get drivers back onto the motorway:
- Follow the M4 westbound to junction 5 (the Langley Interchange)
- Turn around at junction 5
- Return on the M4 eastbound to rejoin the M25 anticlockwise via M4 junction 4b
National Highways warns the route will be busier than usual, with residual delays expected on the M25 on Sunday morning after the closures are lifted. The busiest pinch point is expected around the M25/M4 interchange between 8am and midday on Sunday. Drivers are urged to plan ahead, allow extra time, travel earlier or later in the day, and consider alternatives — including public transport — where possible.
An awkward weekend for the delay
The postponement lands on a busy weekend for the capital’s roads. Drivers who had already reshuffled plans for tonight’s closure now get this weekend back — but they will need to run the same planning exercise next weekend instead.
It is also a Bank Holiday-style double hit for the motorway diary: the M25 has already seen a busy run of planned works this month, including the Dartford-area closures and the earlier multi-vehicle crash at Clacket Lane services, which shut lanes for hours. National Highways says drivers should check Traffic England before setting off on 31 October.
One small mercy for night-time travellers: the clocks go back at 2am this Sunday, 25 October — giving everyone an extra hour overnight. That will not soften the diversion next weekend, but it does mean this weekend’s cancelled closure would have come with an unusually long night for anyone stuck in it. You can read our guide to the clock change here: the clocks go back at 2am tonight.
What to do if you are flying this weekend
If you had planned an airport run for tonight or tomorrow morning around the M25 works, the good news is straightforward: the closure is not happening, so drive as normal. But the postponement is a reminder of how quickly planned works can shift, and anyone flying next weekend should re-plan around the new dates.
For next weekend, the alternatives remain the same as we reported when the closure was first announced: stay on the M4 from the west or south-west to avoid the closed section entirely; from the north, the A4 and local routes into Heathrow are worth checking; or skip the roads altogether — the Elizabeth line, Piccadilly line and Heathrow Express all run unaffected.
National Highways’ advice is worth repeating: work backwards from your flight’s departure time, build in the buffer, and check live traffic on the morning of travel. An overnight closure may sound like it is over before it starts, but a diversion through the M4 at Langley can add serious time to an airport run — and next Sunday, unlike this one, the cones will really be out.
