Know what the wind costs before you drive.
Your EV's range meter can't see the headwind on tomorrow's highway, the 2,000-foot climb at mile 90, or the A/C load of a 95° afternoon. Tailwynd can. Enter a destination and it prices the whole trip in the units you actually think in: "This 157-mile trip will use about 199 miles of your range." Then a live card rides along on your Lock Screen and CarPlay, re-checking the forecast as you drive and pinging you when the wind rewrites your arrival math. No account, no tracking.
New here? The Field Guide walks through setup and every feature in five minutes.
Every force on your battery, accounted for.
Real physics, real forecasts, and a model that learns your car — explained in plain words and range miles, never jargon.
Wind, priced before you leave
Tailwynd checks the forecast at checkpoints along your route — each at the hour you'll actually pass it — and prices headwinds, tailwinds, and crosswinds with real aerodynamics, including the extra drag sideways wind puts on boxy EVs.
Answers in range miles
No cryptic percentages. The verdict reads like your dash: "Expect noticeably less range — this 137-mile trip will use about 163 miles of your range." You instantly know whether to charge first.
Terrain-aware to the hill
A dense elevation profile of your route prices every climb and credits every descent the way an EV really does — regen included, thinner air at altitude included. The route card draws the whole profile.
Heat and cold, counted
A/C on a desert afternoon and heat in winter cost real range. Tailwynd reads the forecast temperature along your route and prices the climate load — plus city stop-and-go versus highway cruising.
A live card for the drive
Hand off to Apple Maps and a trip card appears on your Lock Screen, Dynamic Island, and CarPlay — whole-trip estimate, miles left, ETA, and the current wind with an arrow showing whether it's pushing or fighting you.
Wind-shift alerts
The forecast refreshes every 15 minutes while you drive. When the outlook genuinely moves, the card lights up: "Winds save 21 mi of range" in green, or "Winds cost 9 mi extra range" in red. Silence means steady.
The road ahead, drawn
The live card shows the next 30 miles of terrain as a small graph, so a long climb or a drawn-out downhill never surprises you — and severe weather is pinned in red right on the hill where you'll meet it.
Severe-weather safety
Official National Weather Service alerts — flash floods, severe thunderstorms, winter storms — are checked along your route and flagged by mile before you leave. Worldwide, the forecast is screened for snow, ice, fog, low visibility, and dangerous gusts.
Honest about storms
Near an active thunderstorm, wind direction genuinely can't be forecast — so Tailwynd says "storm outflow, winds variable" instead of showing a confidently wrong arrow. An honest instrument beats a precise-looking one.
Chargers, with reach
See charging stations along your route, each colored by whether your current charge — run through the wind, hills, and weather — actually reaches it. Tap one to reroute.
Your battery, your numbers
Type the charge percent from your dash and Tailwynd predicts your arrival level, marks where the battery runs out, and warns when a trip needs a charging stop. No car account, no cloud connection to your vehicle — ever.
It learns your car
Log your arrival charge after a drive and Tailwynd compares measured against predicted, then calibrates itself to your actual car — your load, your tires, your habits. Predictions tighten with every logged trip.
Trip reports you can share
A shareable route card before you go — verdict, elevation profile, checkpoint winds, battery estimate — and a post-trip report after: measured consumption, model expected, even a check of the forecast against the weather that actually happened.
Any EV, anywhere
Pick your vehicle type — sedan, SUV, pickup, van — and set your battery size once. Weather and elevation coverage is worldwide, units switch between miles and metric, and the app speaks English, Spanish, German, French, and Chinese.
Private by design
No account. No sign-up. No ads. No analytics. Trips and battery logs stay on your phone, and weather lookups carry coordinates only — never your identity.
From doubt to a number in seconds.
Plan, read the verdict, drive, and let the app learn.
Plan the trip
Enter a destination — and the battery percent from your dash if you want arrival estimates. Pick a departure time up to five days out.
Read the verdict
One banner tells you what conditions will do to your range, in miles. The details page has every checkpoint, hill, and hazard.
Drive with the live card
Hand off to Apple Maps and the trip card follows along — updating with fresh forecasts and warning you when winds shift.
Log and learn
Note your arrival charge in the trip report. Tailwynd measures itself against reality and calibrates to your car.
Built on physics. Checked against reality.
Tailwynd isn't a rule of thumb — it's a physical energy model, validated on the road.
A real energy model
Aerodynamic drag with crosswind yaw, rolling resistance, climbing against gravity with regenerative recovery, air density falling with altitude, climate load, and stop-and-go losses — integrated over every mile of your route.
Serious data sources
Hourly forecasts and a 90-meter global terrain model from Open-Meteo, official alerts from the U.S. National Weather Service, and routing from Apple Maps — matched to the hour you pass each point.
Road-tested honesty
Validated on multiple 900+ mile road trips — including a 157-mile leg where the range prediction landed within half a percent and the ETA within 36 seconds. When the app misses, it logs why and learns.