Driving tips Planning a road trip
The order of operations
A weather app can tell you what the sky is doing over your town right now, which is no use when the interesting part of the trip is four hours away. This is the sequence that gets a trip decided — and the sequence matters more than any single reading, because the order you check things in decides which question you are allowed to ask next.
Before anything else
You cannot change the weather. You can change when you drive through it, and you can change which road that is. Every other decision — which jacket, which tyre, whether to cancel — follows from one of these two, or from the answer being no.
Free, reversible, and usually the cheapest fix. Most bad weather on a route is somewhere in the middle of it, and most bad weather in the middle of a route is somewhere in the middle of the day. Moving the departure by three hours often moves the problem off your miles entirely, without changing a single kilometre of road.
The fallback when no hour works. It costs fuel, time and confidence, and it frequently replaces one problem with a smaller one in a place you had not thought to check. Reach for it second, not first.
The procedure
Ten minutes with the app, once, before you commit — and five minutes again on the morning you leave.
Fix the route first — the places you are going are not the variable. Then read the forecast on that route at two horizons. Ten days out tells you which days are viable. Two days out tells you what time.
That gap is real and it is not a quirk of one app. A forecast ten days out is good at saying a stretch of days will be wet and bad at saying which hour on Tuesday. Anyone who tells you otherwise is reading detail off a picture that does not hold it. Use the far end to rule days out and the near end to plan them.
The summary view is one screen of the whole trip: severe weather alerts, high wind and gusts, extreme low and high temperatures, heavy precipitation, poor visibility, and how much of the route falls in the dark, with sunrise and sunset times.
Its job is not to tell you the weather. Its job is to tell you whether this day is worth twenty more minutes. If the summary is unremarkable, it usually is — and you have just saved an hour. If it is not, you now know which thing to go and look at, which is a much better question than “what is the weather going to be”.
This is the step that separates a trip you have thought about from one you have looked at. A summary tells you the trip has bad weather on it. The map tells you where.
Every point along the route has its own forecast, timed to the moment you reach it. So an exposed ridge at the 180 km mark is a specific place with a specific number at a specific hour — not a regional average, and not the weather at the town you are leaving from. Almost every interesting decision on this page happens at one of those points, and you cannot see any of them from the summary.
Four conditions get a guide each, and each one is about where on a route it bites hardest rather than what it is. Jump to which one is yours.
The departure time slider is the useful part of a route-weather app, and the reason is not that it produces a nicer picture. It recalculates your arrival at every point on the route, which means the whole forecast is re-timed rather than re-labelled.
Slide it two hours and you are no longer looking at the same forecast later. You are looking at a different forecast for a different hour, for a place that may be on the other side of a front. One move of the slider often slides the whole rain band off your miles. It also changes how much of the trip is in the dark, which is worth watching deliberately rather than as a side effect.
Look at several hours, not one. “Better at 06:00” is worth much less than “flat until 09:00, then bad, then flat again” — because the second one tells you there is a window, and you can build the rest of the day around it.
When no departure time works, compare the main alternative routes side by side — each with its own travel time, distance and forecast, so you can see whether the second road goes around the weather or just through it later. Sometimes the alternative is also the faster one, which is the good outcome.
The order still matters. A detour costs fuel, time and the part of the day you had planned, and the road you switch to is one you have not checked for its own problems. So switch routes when no hour on the good road works — not on the first hour that looks uncomfortable.
Almost everyone plans the departure and arrives somewhere they did not check. The last hour of the day is often a different situation from the first: the temperature where you stop, whether that is below freezing once the sun has gone, and how much of the final stretch is in the dark.
On a multi-day trip this is the step that gets skipped, because each day's route is planned the night before and the forecast for tomorrow evening is not yet the thing you have looked at. Plan it anyway. A campsite at −4 °C with a night-time arrival is a different trip from the same campsite in daylight, and the difference is a forecast you already had and did not read.
Why a pass is not the weather of the town at its foot — the same idea, on the vertical axis.
Look again the day you leave, close to it. The forecast you planned on is the one most likely to be wrong, and a changed forecast is information rather than bad luck: if the plan you made no longer holds, the thing that changed is the weather, not your judgement. Re-run steps 2 to 4. It takes five minutes.
Then decide what a forecast cannot decide for you. Wayther forecasts weather. It does not know what a road authority has closed, it does not report the temperature of the road surface, and it does not carry official warnings. Where your area issues weather warnings, those are the record of what has been officially judged dangerous and they are the source to follow. And where a road is closed, it is closed because somebody decided it was — which is a decision, not a forecast, and the right one to defer to.
Sometimes every hour is bad and every road is worse. That is a real answer, not a failure of planning, and the trip waits.
Step 3, in detail
The four guides cover what each condition does and, more usefully, where on a route it costs you the most. Read the one that matches, then come back to step 4.
Wind
Ridges, bridges, gaps and open water, where the ground cannot slow the air down. Read the direction as well as the speed: the same number is a free tailwind on one road and a fight on another.
Rain
The easiest condition to plan around, because a shower has a beginning, an end and a direction it travels in. Find the edges of it on your miles and check whether they are edges you can drive past.
Fog and visibility
Two kinds with opposite answers. Radiation fog burns off with the sun; advection fog arrives from a sea or a warm front and does not care what time you leave.
Snow and altitude
The pass is not the weather of the town at its foot, and the freezing level moves during the day. The best hour to cross is usually later than the hour you would guess.
Or read all four in one pass on the Driving Tips page.
Worked example — invented to show the method
You are driving a loop on Saturday: out on Saturday morning, over a pass, down to the coast, one night in a hotel, back on Sunday. Nothing about that is hard. Everything about it has three decisions in it.
The summary is unremarkable apart from one thing: a block of poor visibility, four hours long, sitting across the middle of the route. Not a warning. A grey patch in the middle of a good day.
That is enough to keep reading, and not enough to change anything yet. Step 2 done: keep looking.
On the map, the pass itself is unremarkable at your planned arrival: above freezing, light wind, clear. The visibility block starts after it and runs to the coast.
So the pass is not your problem and the middle of the day is. The useful observation is that the block has an end, and it ends before you reach the coast.
Move the start three hours later. The whole route re-times: you reach the pass around midday instead of early, which makes it warmer and no worse, and you reach the far edge of the visibility block at −2 °C with the sun out behind you.
Move it two hours later again and it gets worse — the block arrives back over your last stretch in the dark. So there is a window, and the window is wide enough for the trip but not for a four-hour detour behind it.
The return is the same road in reverse, which means the same weather in a different order, and that is worth checking before booking the hotel. Sunday afternoon is worse than Saturday afternoon on the same miles. Leaving earlier on Sunday fixes it, and the hotel does not move.
Saturday morning, the block has shifted two hours later and grown. The window is still there but narrower. You re-run steps 2 to 4, move the departure ninety minutes earlier to keep the margin, and go.
Note what did not happen. The route did not change, the hotel did not change, and no decision was reversed except a number on a slider. The whole re-plan was five minutes.
Three hours of data, two passes over the same forecast, no new information — just read at a different resolution. That is the whole method. If your planning ever needs more than that, something in the trip is not actually flexible, and that is worth knowing before you leave rather than at the pass.
Questions this raises
Far enough to rule days out, close enough to plan them. Wayther plans up to 10 days ahead. At the far end of that range the forecast is reliable about the general character of a stretch of days and unreliable about which hour of which day; near the end it is the other way round. A trip ten days out should have its days chosen and its hours left open. A trip tomorrow should have both.
Then the road becomes the lever, and you should compare the alternatives properly rather than assuming the main route is the best one. Wayther shows the main options side by side with their own travel time, distance and forecast. It is worth remembering that a detour is not free: it costs the part of the day you had planned, and the road you switch to has its own wind, its own rain and its own night.
Yes, and this is the step people skip. On a five-day trip the fifth day is usually planned on the fourth evening, which is too late to do anything about it except notice. Each day has its own arrival times at its own places, and the same stretch of road is a different problem when you meet it going the other way at a different hour.
It is a planning app, built to be read before you set off and then glanced at from the passenger seat or at a stop. It is not a navigation app — keep your maps app for turn-by-turn directions — and it is not a source of official warnings. Follow the weather warnings your own area issues.
Every step above needs the same thing: the forecast at every point along your route, timed to when you get there. Try every feature on a random route, free.
Forecasts come from Apple Weather and cover wherever Apple Weather is available, in metric or imperial units, up to 10 days ahead. Wayther plans a trip; it does not navigate and it does not report closures. Keep your maps app for directions, and follow official weather warnings and road closures.
