Route Planner
A forecast for your destination says nothing about the pass you cross three hours before you get there. This planner reads the weather for the hour you reach each stretch of the drive, in that stretch’s own time zone, and colors the route by what it finds.
How to check the weather along your drive
- Enter your start and destination. Add stops in between if you need them. The planner builds the route, with an alternative or two where one exists, and reads the forecast about every 25 miles along it.
- Set your departure time. Every point on the route is then matched to the hour you will actually be there — not to the forecast for right now.
- Read the drive hour by hour. The line turns green, amber or red by the conditions at the hour you reach each stretch, and the timeline under the map shows rain, temperature, wind and the estimated pavement condition, so you see where the weather changes mid-route rather than one figure for the whole trip.
- Compare departure times. The planner scores several start times on the same route. Moving the start by two or three hours can take the whole drive out of the worst of it.
Best time to leave
Moving your start changes more than the weather at your door: it changes the hour you reach the hardest stretch of the drive. So the planner runs the same route from 5 AM, 8 AM, 11 AM, 2 PM, 5 PM and 8 PM on the day you choose, in the time zone you leave from, plus the time you typed, each at its own pace. Each option is scored by the average conditions along the whole drive and by the worst one it meets, because a drizzly day and one icy bridge can average out the same.
Seattle to Boise shows why. Snoqualmie Pass is about an hour out of Seattle on I-90, so if snow is forecast to reach the summit mid-morning, a 5 AM start has you over it first and an 8 AM start puts you there as it arrives — the same day, the same forecast, a different drive. Click any option to move your departure there.
What the hour-by-hour timeline shows
Once a route is drawn, a timeline opens along the bottom of the map. Drag the slider or press play and a car moves along the route while the map’s weather layer moves to the same hour. Its lanes show the precipitation rate and how much has fallen, the air temperature beside the estimated pavement temperature, and wind speed and direction; the full view adds cloud cover and pressure. The buttons above the map wash it with forecast precipitation, wind or temperature, and before you plan anything precipitation is the live radar.
A stretch the forecast does not reach yet stays blue rather than being shown as safe, and the summary says how far along the drive the forecast goes. National Weather Service alerts that touch the route are listed above the summary and pinned on the map where they apply.
Elevation profile: where rain becomes snow
Air cools by roughly 3 to 5 °F for every 1,000 feet you climb, so rain at 38 °F in a valley can be snow a couple of thousand feet higher up. That is how a drive forecast as wet turns white at the summit. The elevation profile draws the climbs and descents of the whole route, marks its highest point and gives the forecast temperature and weather there at the hour you pass, with the total feet of climbing. On a route through the Rockies or the Cascades, read it with the pavement temperature in the timeline.
Suggested rest stops
The planner suggests a stop every two hours of driving — up to five, none in the last half hour — named after the nearest town within 25 miles, or by its distance along the route where there is none. The stops are spaced by time, not picked by the weather, but each shows the forecast for the hour you would get there. When snow or a line of storms lies across the route ahead, the stop before it is the place to wait it out rather than drive through it.
State road reports and 511
Weather is half of it; closures, crashes and construction come from each state’s DOT. Once a route is planned, the results list every state it crosses, each linked to our page for that state with its 511 closures and DOT cameras. Chicago to Denver runs through Illinois, Iowa, Nebraska and Colorado; Seattle to Boise through Washington, Oregon and Idaho. Every state and interstate is on the road conditions page.
In the car: CarPlay and Android Auto
The planner is for before you leave. On the road, Weather Navigation for iPhone and Android puts live radar, road conditions, 511 alerts and an hour-by-hour driving forecast on the car’s screen through Apple CarPlay and Android Auto.
Driving weather FAQ
Yes. Weather Navigation for iPhone and Android shows live radar, road conditions and 511 alerts along your route, on the phone and on the car’s screen through Apple CarPlay and Android Auto. This planner is its web half: the forecast for a drive you have not started yet, at the hour you reach each stretch.
Yes. The Federal Highway Administration counts about 12 percent of US crashes as weather-related — nearly 745,000 a year, with more than 3,800 people killed — and over three quarters of those happen in rain or mist, not in snow or ice. Rain cuts visibility and grip, wind pushes high-sided vehicles across the lane, and bridges ice before the road around them. (FHWA, five-year averages for 2019–2023.)
In the US the reference is NOAA’s network of NEXRAD Doppler radars, which nearly every weather app draws on. NOAA’s MRMS system merges all of them with rain gauges and satellite data into one mosaic every two minutes, and that is the radar on our road-condition pages. Radar only shows what is falling now, though: for a drive you are planning, the forecast for the hour you will be there is the better guide, which is why this planner switches to the forecast once a route is drawn.
Set the departure date to tomorrow and the time you plan to leave, then press Show route weather. Every stretch is matched to the hour you will reach it, in its own time zone, so a 7 AM start shows the morning on the first miles and the afternoon at the far end. The date can be up to two weeks ahead; the summary says how far along the drive the forecast reaches.
Yes. The route is drawn on a map and colored green, amber or red stretch by stretch, with weather bubbles along it giving the temperature, the sky and the clock time you will be there, and warning marks where ice, snow or wet pavement is forecast. The buttons above the map wash it with forecast precipitation, wind or temperature for the same hour.
Yes, before you plan: the map opens on the live radar mosaic. Once a route is drawn it switches to the forecast, because every mile ahead is reached at a later hour and radar can only show the present. For live radar while you drive, the app shows it on CarPlay and Android Auto, and our road-condition pages show it along each highway.
Enter a start and a destination, set when you leave, and press Show route weather. The planner reads the forecast about every 25 miles, each point for the hour you will be there, and colors the route by what it finds.
Yes. This planner is free, with no account, no sign-up and nothing to install: routes and alternatives, the hour-by-hour forecast, the departure comparison, rest stops and a link to share the plan all work in the browser. The Weather Navigation app is free to download too; its PRO version adds live radar without the free version’s two-hour delay.
It depends on the route and the day, which is why the planner scores six start times on the day you choose, plus your own, for yours. The hour you reach the highest or most exposed stretch usually matters more than the hour you leave, and on a winter route the pavement is coldest around dawn, so an early start can trade snow for ice.
Yes, through the Weather Navigation app, which runs on Apple CarPlay and Android Auto with live radar, road conditions and 511 alerts ahead of you. This planner is a web page for before you leave: plan the drive here, then drive it with the app.