Written by Tommo, Verus founder · Last verified August 2026 · 7 min read

Running Guide

Britain's Real Running Constraint Isn't Rain, It's Daylight

Quick Answer

London records rain on about 132 days a year and, in eleven years of records, has never averaged a start-line temperature at or above 24°C in any month. Britain is almost never heat-limited or rain-limited. What genuinely constrains running here is daylight: London gets under eight hours at the winter solstice and Edinburgh under seven.

British runners complain about the weather more than almost anyone and are wrong about which part of it matters. The rain is an inconvenience. The temperature is, by international standards, close to ideal. The thing that actually shapes a British running year — that decides when you can train, what you have to carry, and which four months of the calendar are effectively a different sport — is how much light there is.

The temperature is not your problem

Verus keeps an eleven-year archive of daily conditions for the places it covers, sampled at the hours people actually set off. Here is London, which is the warmest major city in Britain and therefore the least favourable case.

MonthAvg highAvg lowRain days06:00 temp / dew08:00 temp / dew
January7.6°C1.8°C11.63.6 / 2.03.5 / 1.9
February9.1°C2.7°C12.04.2 / 2.44.2 / 2.4
March11.1°C3.9°C11.94.9 / 3.05.2 / 3.3
April14.2°C5.1°C9.25.6 / 3.87.6 / 4.7
May17.6°C8.6°C10.89.3 / 7.511.8 / 8.2
June21.2°C12.0°C10.412.9 / 10.815.2 / 11.3
July22.8°C14.2°C10.414.8 / 12.517.0 / 12.9
August22.4°C13.9°C9.214.3 / 12.616.3 / 13.3
September19.6°C11.6°C11.212.3 / 10.813.4 / 11.4
October15.5°C8.9°C11.410.2 / 8.710.4 / 8.9
November11.1°C5.4°C11.97.1 / 5.57.1 / 5.6
December9.3°C4.4°C11.76.0 / 4.56.0 / 4.5

Verus counts a "warm morning" as one starting at or above 24°C — the point where heat stops being a detail and starts setting your pace. Across eleven years and all twelve months, London's figure is zero. Not low. Zero.

Dew point tells the same story. The measure that governs how well you shed heat peaks at 13.3°C at eight in the morning in August. Below 10°C is air you barely notice; it takes above 20°C before evaporative cooling is meaningfully compromised. Britain does not get there at the hours people race.

The caveat that matters

These are averages, and averages hide heatwaves. A British summer now produces days that genuinely are dangerous to race in, and races get cancelled or shortened for it. The point is not that Britain never gets hot — it is that heat is an occasional emergency here rather than a permanent planning constraint, which is the opposite of how most running advice treats it.

The rain costs you less than you think

London records rain on about 132 days a year. That is a lot of days and not much rain — the British pattern is frequent and light rather than occasional and torrential, and the wettest month (February, at 12.0 days) is barely wetter than the driest (April and August, both at 9.2).

Rain costs you almost no pace. It costs comfort, it ruins feet over a long day if you have not thought about socks, and it makes rock and root genuinely dangerous — which matters enormously on a fell descent and not at all on a road 10K. The correct response to British rain is better socks and a windproof, not a changed plan.

Daylight is the constraint

Here is what actually shapes the year. Britain sits between roughly 50°N and 59°N — further north than almost anyone realises, level with Labrador and southern Alaska — and the seasonal daylight swing that comes with that latitude is extreme.

PlaceLatitudeDaylight at winter solsticeDaylight at summer solstice
London51.5°Nabout 7h 50mabout 16h 38m
Manchester53.5°Nabout 7h 20mabout 17h 00m
Edinburgh55.9°Nabout 6h 57mabout 17h 36m
Inverness57.5°Nabout 6h 35mabout 18h 10m
Lerwick, Shetland60.2°Nabout 5h 49mabout 18h 55m

For anyone working ordinary hours between November and February, that means every midweek run is a night run. Not dusk — dark. And in the north of Scotland it means a working week in which you may not see daylight outdoors at all.

This is the single biggest practical difference between a British running year and one in southern Europe, and it drives things that look like unrelated cultural quirks:

  • Why British club nights are on weekday evenings with headtorches, and why club runs matter more here than in sunnier places — running in the dark alone is a different proposition to running in the dark in a group.
  • Why the winter racing calendar is dominated by cross country and short road races rather than long ones: there is no long midweek run to be had in daylight.
  • Why the hardest British ultras are deliberately staged in winter. The Montane Winter Spine in January and the Arc of Attrition in Cornwall are not hard because of cold — they are hard because roughly fourteen of every twenty-four hours are dark.
  • Why the racing season swells so abruptly around the clocks changing in late March.

Practical

Buy the headtorch in October, not in January when you have already skipped three runs. A 200-lumen torch and something reflective converts four months of the year from unusable to ordinary, and that is a bigger training gain than almost anything you can buy.

Wind, and where it matters

The other underrated variable. Britain sits in the westerly belt with the Atlantic upwind, and on any exposed coast or ridge the wind will affect your time more than the gradient does. The west coasts of Scotland, Wales and Cornwall are where this bites hardest, and an out-and-back with a strong westerly is one of the easiest ways to ruin a race by feeling wonderful for the first half.

How much Britain varies within itself

London is not Britain. Roughly, and usefully: the south-east is the driest and warmest; the west — Cornwall, Wales, Cumbria, western Scotland — is markedly wetter, because that is where the Atlantic air hits high ground first; the east coast is drier but colder and windier; and the Scottish Highlands are a genuinely different climate that holds snow on high ground into May.

The practical consequence is that a fell race in the Lakes and a road 10K in Kent are not just different races, they are different weather systems. Plan the western and northern ones with more kit than the forecast suggests.

Frequently Asked Questions

How many days a year does it rain in the UK?

London records rain on about 132 days a year, spread evenly — 12.0 days in the wettest month against 9.2 in the driest. The west and north are significantly wetter than the south-east.

Does it get too hot to run in Britain?

Very rarely at the hours people run. In eleven years of London records, no month averages a start-line temperature at or above 24°C, and peak dew point is 13.3°C. Heatwaves do happen and can genuinely be dangerous, but heat is an occasional emergency here rather than a planning constraint.

How much daylight does the UK get in winter?

About 7h 50m in London at the winter solstice, 6h 57m in Edinburgh and 5h 49m in Lerwick. For anyone working ordinary hours that means every midweek run between November and February is a night run.

Why are the hardest British ultras held in winter?

Darkness, not cold. The Montane Winter Spine in January and the Arc of Attrition in Cornwall are hard largely because roughly fourteen of every twenty-four hours are dark, which compounds navigation, sleep deprivation and cold together.

Is rain or wind worse for running in Britain?

Wind, by a wide margin. Rain costs almost no pace and mostly costs comfort. Wind on an exposed coast or ridge will affect your time more than the gradient, particularly on the west coasts of Scotland, Wales and Cornwall.

How much does British weather vary by region?

Considerably. The south-east is driest and warmest, the west — Cornwall, Wales, Cumbria, western Scotland — markedly wetter where Atlantic air meets high ground, the east coast drier but colder and windier, and the Scottish Highlands a different climate again, holding snow on high ground into May.