Reading wind and weather before you ride: how to plan your route

Two rides with identical distance and elevation can feel like two different sports depending on how hard the wind blows. Checking the forecast before you leave is not a hobbyist’s obsession: it is the cheapest way to save energy, avoid nasty surprises and enjoy the ride more.

Why wind matters so much

On flat roads, most of your effort goes into pushing through the air. That resistance does not grow in proportion to speed; it grows much faster. The force rises roughly with the square of your speed relative to the air, and the power you need rises roughly with its cube. That is why a moderate headwind forces you to pedal noticeably harder to hold the same pace, or to ride a lot slower at the same watts.

There is bad news on top of that: a tailwind does not give back everything a headwind takes away. Ride an hour into the wind and an hour with it behind you, and the balance usually comes out worse than on a calm day.

Headwind, tailwind and crosswind

Headwind: the one that hurts most. It lowers your speed, raises your perceived effort and makes the kilometres drag. On a long, exposed stretch it can decide how your day ends.
Tailwind: it pushes you along and lets you roll fast with little effort, but it is deceptive. It is easy to overcook the pace without noticing, and with little airflow over your body you sweat more than you think.
Crosswind: it slows you less, but it makes you correct your line, keep your hands tense and watch for gusts, especially in open country, on bridges, at tunnel exits or when a truck overtakes you. Deep-section wheels make it more noticeable.

Besides the average wind, look at the gusts: a steady 15 km/h is one thing and gusts of 45 km/h are another entirely, even if the average looks reasonable.

Plan the direction of your route

A simple and very useful rule: head out into the wind and come home with it behind you. If you start with a tailwind, you will not find out how hard it blows until you turn around, and by then you are tired, far from home and facing all of it.

Out-and-back: plan the outbound leg against the wind, or in a crosswind, so the return, when you are most tired, is the comfortable part.
Loops: the same loop can be ridden in either direction. Choose the direction that puts the longest exposed sections in the first half and the sheltered or downwind sections at the end.
Mountains and valleys: wind is channelled and accelerated through passes, ridges and valley floors. A climb that is sheltered in the morning can be a different story in the afternoon.
Start time: in many places the wind tends to pick up around midday and in the afternoon. An early start can give you a calmer window.

How Cyklot shows it

On the page of every route that has a track you will see the Weather and wind card. Here is what it does, no more and no less:

It asks Open-Meteo for an hourly forecast at a few points spread along the route: three if the route is shorter than 25 km, five from 25 km onwards.
You choose the day and hour: today and the next 7 days. Beyond that there is no forecast.
For each point it shows temperature, precipitation in millimetres and chance of rain, the sky conditions, wind speed, gusts and where the wind comes from.
It works out the wind relative to your direction of travel: each stretch of the track counts as a headwind if the wind comes from roughly where you are heading (within about 45 degrees), as a tailwind if it pushes from behind (from 135 degrees up), and as a crosswind otherwise.
It sums everything up in a bar showing the share of the route against, across and with the wind, plus a line with the average net wind, for example how many km/h are against you on average.

Results are cached for about 30 minutes, so reloading the page does not query the provider every time. If the forecast is unavailable at that moment, the card says so and lets you try again, while the rest of the route keeps working.

One honest caveat: the forecast is for one specific hour across the whole route. On a long ride the wind can turn or change strength while you are out, so if you will be riding for four or five hours, compare two or three different hours, not only your start time.

Temperature, rain and layers

The temperature in the forecast is not the temperature you will feel. At 30 km/h the air cools you far more than when you stand still, and on a long descent the feeling drops even further. Dressing well is a matter of layers:

Light base layer: a first layer that moves sweat away keeps you dry, which is half of staying warm.
Jersey and add-ons: arm warmers, leg warmers and shoe covers come off and fit in a pocket. They are more versatile than one thick garment.
Wind vest: it weighs little, packs small and protects exactly where the cold gets in, your chest. It is the garment with the best usefulness for its weight.
Light rain jacket: if the chance of rain is high, bring it even when the sky is clear as you leave.

As a general guide, set off feeling slightly cool: ten minutes in you will be at temperature. If you leave perfectly comfortable, you will probably overheat.

Rain changes more than your clothing. Wet tarmac reduces grip and lengthens braking distances, painted lines and manhole covers get slippery, and visibility drops. Slow down in corners and on descents, leave more space and use lights even in daylight.

When to reschedule

Sometimes the best decision is not to ride, or to ride another day. These signs are good reasons to move it:

Strong gusts, especially if your route includes exposed sections, bridges or technical descents.
Thunderstorms forecast during your ride window.
Freezing rain, snow or temperatures near zero with possible ice.
Dense fog on roads with traffic.
A high chance of rain combined with real cold and a route far from any shelter.

If you have a structured workout you do not want to lose, it can often be moved a day or done on a trainer. Shifting a day does not ruin a plan; riding in bad conditions might. Use your judgement and, when in doubt, put safety first.

Next step

Open one of your routes in Cyklot, check the weather and wind card for the day and hour you have in mind, and decide which way to ride before you grab the bike.