Agile Octopus in winter: how prices change from summer
Agile Octopus winter prices run higher than summer prices, and the cheap hours move. Last winter, London's Agile price averaged 19.15p/kWh, against 16.94p/kWh the summer before. The cheapest time of day shifted from midday to the middle of the night.
Summer and winter side by side
The table compares summer 2025 (June to August) with winter 2025 to 2026 (December to February) in London (region C). Both periods include the 5% VAT that applied then, so they compare like for like.
| London | Summer 2025 | Winter 2025–26 |
|---|---|---|
| Average price | 16.94p/kWh | 19.15p/kWh |
| 4pm to 7pm average | 28.92p/kWh | 34.12p/kWh |
| Half-hours below 10p/kWh | 11.9% | 4.0% |
| Negative half-hours | 102 | 2 |
| Dearest half-hour | 55.31p/kWh | 63.84p/kWh |
January was the most expensive month, at 21.54p/kWh on average. The dearest half-hour of the winter came at 4:30pm on 8 January 2026.
The cheapest hours move
The biggest practical change is when power is cheapest. In summer, the 12pm to 4pm block was the cheapest of the day. In winter, it was midnight to 4am.
| London, time of day | Summer 2025 | Winter 2025–26 |
|---|---|---|
| Midnight to 4am | 14.39p/kWh | 14.51p/kWh |
| 4am to 8am | 15.33p/kWh | 16.07p/kWh |
| 8am to 12pm | 14.40p/kWh | 18.71p/kWh |
| 12pm to 4pm | 11.22p/kWh | 18.44p/kWh |
| 4pm to 7pm | 28.92p/kWh | 34.12p/kWh |
| 7pm to midnight | 19.62p/kWh | 17.25p/kWh |
Overnight prices barely changed between the seasons. Midday rose by more than 7p/kWh, and late evening actually got slightly cheaper.
So anything you ran at lunchtime over the summer, such as a dishwasher, car charge or hot water, is likely to be cheaper overnight this winter. The cheapest times to run an appliance today are worked out from each day's real prices.
Weekends stop helping
In summer, the weekend evening peak in London averaged 27.54p/kWh, about 2p below weekdays. In winter there was almost no gap: 33.83p/kWh at weekends against 34.24p/kWh on weekdays.
Negative prices, where you are paid to use power, almost disappeared too. London had 102 negative half-hours last summer and just 2 last winter.
Northern Scotland follows the same pattern
Northern Scotland (region P), which has some of the highest Agile prices in Britain, moved the same way from a higher starting point.
| Northern Scotland | Summer 2025 | Winter 2025–26 |
|---|---|---|
| Average price | 20.01p/kWh | 22.66p/kWh |
| 4pm to 7pm average | 32.19p/kWh | 38.43p/kWh |
| Cheapest block | 12pm to 4pm, 13.47p/kWh | Midnight to 4am, 17.41p/kWh |
You can compare Agile prices across all 14 regions for any day.
What is different this winter
Two things will change the numbers this year. First, household electricity in Great Britain carries no VAT from 1 October 2026 to 31 March 2027, so prices no longer include the 5% VAT that last winter's did.
Second, Octopus says capacity market costs apply to weekday 4pm to 7pm use from November to February. These pay to keep enough generating capacity available, and they land in the same hours as last winter's highest prices.
You can follow this winter month by month in the Agile price history charts.
FAQ
Is Agile Octopus more expensive in winter? Yes, on average. In London, last winter averaged 19.15p/kWh against 16.94p/kWh the summer before, both including 5% VAT.
What is the cheapest time on Agile in winter? Usually overnight. Last winter, midnight to 4am averaged 14.51p/kWh in London, the lowest block of the day.
Do negative Agile prices happen in winter? Rarely. London had 2 negative half-hours from December 2025 to February 2026, against 102 in summer 2025.
Is the Agile evening peak worse in winter? Yes. London's 4pm to 7pm average rose from 28.92p/kWh in summer 2025 to 34.12p/kWh in winter 2025 to 2026.