About WeatherItinerary

I'm Leo Vicente — a software engineer, a geek, and a traveller who got tired of a very specific problem.

Checking the weather before a trip is easy. Open an app, look at the forecast, done. That works fine when you're going to one place. But the moment your itinerary covers multiple cities — or multiple countries — it starts to fall apart. You're switching between tabs, copying dates across apps, trying to mentally stitch together what the weather looks like across your whole trip. No app gives you a single view for all the cities you're visiting at once.

So I built one.

I started working on WeatherItinerary on a train from Vienna to Munich in December 2025 — mid-way through a Christmas and New Year's trip across Europe where I was doing exactly that: juggling apps for each stop. Here's that actual trip — it was the first real itinerary I planned with the tool while building it.

That trip is also why WeatherItinerary now has a Christmas market mode: every market in Europe with its opening dates checked against the organisers' own pages, and a route generator that chains the ones open on your dates. Browse the markets or generate a route.

Without any marketing, people started signing up. That told me the problem was real and I wasn't the only one running into it.

How the weather data works

The weather data works in three tiers. For the first couple of weeks out, you get a real forecast — sourced from the best-performing models for each location, drawing from national agencies including NOAA (US), ECMWF (Europe), DWD (Germany), Météo-France, and Environment Canada. From there out to around seven months, it's extended-range: a seasonal model estimate, less precise than a forecast but still grounded in current model runs. Beyond that — out to 24 months — the app switches to climatology: what the weather has actually done at that time of year, averaged across the last decade of historical records. Every date is labeled with which of the three you're looking at, so you always know whether it's a prediction, an estimate, or a pattern.

The confidence indicator on each forecast reflects how far out you're planning and how much the models agree with each other. Close to your travel dates, it's high. Six months out, treat it as guidance, not certainty. For the full breakdown — sources, the Travel Window Score formula, and where our numbers can differ from official station normals — see How We Forecast.

Say hello

Questions, bugs, or ideas — reach me at leo [at] weatheritinerary.com. I read everything.