Climat

A native, ad-free, open-source weather app for Linux and Windows. Two weeks of forecast as charts you can read, and official severe-weather warnings on every screen where they matter.

Status: early. Version 0.1.0, and the version number is honest. This installs, runs and shows you real weather, and several things the plan calls for are not built yet. What is missing is written down rather than left to be discovered.

Every image in this README is rendered from the running application by scripts/shots.sh, and CI re-renders and diffs them. They cannot drift from what the app actually draws.

• Hourly and ten-day forecasts: temperature, precipitation, wind, humidity, pressure, visibility, UV and air quality, as charts rather than a grid of numbers.

• Severe weather warnings, live, from Environment and Climate Change Canada and the United States National Weather Service. No API key, no account, no server of ours in the middle. Off by default, they can also interrupt you: a desktop notification when a warning arrives and Climat is not on screen, through the XDG portal where there is one and the notification service where there is not.

• Detail cards for sunrise and sunset, the moon phase, and each measurement in turn.

• A dark and a light theme, following the desktop's own setting through the XDG portal.

• Preferences: a gear beside the place name on the desktop, or the Me tab on a phone. The background can follow the sky over the place on screen or hold still; the clock is 24-hour or AM/PM everywhere at once, tiles included; and units are °C or °F as a pair of presets over five independent preferences, so °C with mph or inches of rain with millimetres of visibility is one tap and not an impossibility.

• Phone, tablet and desktop layouts: one product, three arrangements, chosen by the width of the window.

• Ten desktop widgets, drawn from the same components as the app, pinned under your windows on GNOME by a shell extension that draws no weather itself, and on KDE, Sway, Hyprland and every other wlroots compositor by the tiles asking for it directly. One process fetches; every tile and the top-bar indicator read from it over the session bus, so a desktop full of widgets is one client of the forecast service and not eight.

• climat-cli: the forecast for a status bar, a script or a terminal. climat-cli now, hourly, daily, places; --json and --csv for a script, in canonical units so a preference nobody opened cannot move a number something parses. It reads the same cache the app fills, so a status bar polling every minute is not a second client of the forecast service.

• "Use my location" through GeoClue2 on a desktop and through the org.freedesktop.portal.Location portal inside a Flatpak. Your own desktop asks you, once, and the app is told a city and never a street.

• Offline-first. It renders from its cache and reconciles with the network, so a service being down is never an empty screen.

• No ads, no news feed, no telemetry, no account, no API key.

Stated here rather than at the bottom, because a README that lists a roadmap as if it were a feature list is the thing this project is trying not to be.

• No radar or map. The Maps tab renders a deliberate placeholder that says so. This is the single largest gap against the goal in docs/01-landscape.md.

• No model comparison. Showing ECMWF against GFS against ICON with ensemble ranges is the differentiator this project exists for, and it is not built.

• No macOS build to download. It compiles and its tests run on macOS in CI; what is missing is notarisation, which needs an Apple Developer ID, and without it Gatekeeper refuses a downloaded app rather than warning about it.

• The Windows build is unsigned, so SmartScreen warns on first run.

• Android warns you only while the app is open. The package builds, signs, installs and runs on an emulator, and has not yet been checked on a physical phone. Delivering an alert to a sleeping phone is the gate, and Qt has no answer for it. The desktop answer above does not port: it is a session bus and a window that can be hidden.

• No translations. Every string is marked and the catalogue is kept current by CI (325 of them), and not one language has been translated. A machine translation would be worse than none.

• The widgets have never been pinned on a KDE session. They pin themselves on GNOME, which was measured by hand, and on wlroots, which is measured in CI against a headless compositor. KWin implements the same protocol and nobody has run it there.

All of them, with what would close each: docs/known-gaps.md.

Every build is on the latest release, with SHA256SUMS and build provenance beside it.

Flatpak is the primary channel. It brings its own Qt, so it works on any distribution, including Ubuntu 24.04, which ships Qt 6.4 and cannot run the .deb.

flatpak install --user ./climat-0.1.0-x86_64.flatpak
flatpak run io.github.JowiAoun.Climat

Debian 13 / Ubuntu 26.04 or newer, using the distribution's own Qt:

sudo apt install ./climat_0.1.0_amd64.deb

It declares libqt6core6t64 (>= 6.8.2) and apt will refuse to install it on anything older. That is the intended behaviour: a package that installed and then would not start is worse than one that says why.

Download the .msi and run it. It installs per-user, so it needs no administrator rights.

Windows will show an "unknown publisher" warning. The build is not code-signed, because signing requires a certificate this project does not have. The mitigations are listed in the order they should be attempted; in the meantime every release carries SHA256SUMS and GitHub build provenance:

gh attestation verify climat-0.1.0-windows-x64.msi --repo JowiAoun/climat

That proves the file came out of this repository's release workflow at a named commit. It is weaker than a signature in one way (Windows does not check it) and stronger in another, since it names the source revision.

Desktop: one scrolling column, the chart card open on Overview	Phone: five destinations under a nav bar
Tablet: two content columns, bottom bar	Tablet, turned: the nav becomes a left rail

Desktop widgets: six of the ten. On GNOME a shell extension launches Climat's own Qt process and pins its window below everything else; it draws none of this itself, because GNOME Shell cannot host a QML surface. On KDE and every wlroots compositor the same binary asks for a desktop-layer surface and there is no extension at all. docs/widgets.md has both mechanisms and the measurements.

The tablet is not a third layout. It is the phone's shell with two questions answered differently: how many content columns the width buys, and whether the navigation is a bar or a rail. See docs/10-design-system.md §10.12.

Everything goes through a Nix devshell, which pins Qt, the compiler, FreeType and fontconfig by store hash, which is what makes the golden images reproducible on a machine that is not this one.

nix develop --command cmake --preset dev
nix develop --command cmake --build build/dev
scripts/dev-run.sh                             # builds if needed, finds Qt itself

scripts/dev-run.sh is the one entry point that works from a plain shell. Running build/dev/app/climat directly outside nix develop exits silently, because Qt is only in the Nix store and the binary cannot find its QML imports.

Try the layouts and the themes:

scripts/dev-run.sh --viewport mobile
scripts/dev-run.sh --viewport tablet-landscape --scheme light
scripts/dev-run.sh --place "Halifax"           # live ECCC alerts
scripts/dev-run.sh --fixture seattle           # four NWS alerts, offline

The desktop tiles are a second binary reading from a third: a weather service the session bus starts on demand once Climat is installed. Nothing is installed in a build tree, so this starts one beside them:

scripts/widgets-run.sh                         # the tiles, with a daemon to read
CLIMAT_FIXTURE=toronto scripts/widgets-run.sh   # …from recorded data

Without a Nix devshell, any Qt 6.8 or newer works; BUILDING.md has the distribution package lists and the CMake options.

nix develop --command ctest --test-dir build/dev --output-on-failure

42 tests, 318 QML assertions among them, and 53 golden images compared byte for byte. The component gallery is a second binary and the fastest way to look at anything in isolation:

CLIMAT_BINARY=build/dev/gallery/climat-gallery scripts/dev-run.sh

It has a touch-target overlay that draws every tap area a layout leaves under 44 px, which is how nine undersized controls were found, including a 14×14 disclosure chevron on every phone screen.

C++20 engine (libclimat, GUI-free and enforced by a CMake assertion) under a Qt 6.8+ / QML interface, with a hand-written scene-graph chart kit. Open-Meteo is the primary forecast provider with MET Norway as a fallback. In Canada, temperature, humidity and wind are the average of Open-Meteo's best match, ECCC's GEM and ECMWF's IFS. Scored against ECCC's own station records, that cut the temperature error by about a fifth (docs/02-data-sources.md §2.10). Alerts are region-routed to ECCC and the NWS. Reverse geocoding is offline, from a 412 KiB bundled GeoNames index, so turning a coordinate into "Toronto, Ontario" never leaves the machine.

There is no server. There never will be: every request goes from your machine to a public weather service, and nothing goes anywhere else.

Weather from Open-Meteo (CC-BY 4.0), which aggregates ECMWF, NOAA, DWD, Météo-France, the UK Met Office and fourteen more national services; in Canada, ECCC's GEM and ECMWF's IFS through Open-Meteo as well; MET Norway as fallback; alerts from ECCC (ECCC Data Server End-use Licence) and the US National Weather Service (public domain); place names from GeoNames (CC-BY 4.0).

Every source is credited at runtime under Data sources, in Preferences on the desktop and on the Me tab on a phone, generated from the provider registry rather than maintained by hand. The full record is in docs/02-data-sources.md §2.9 and §2.10.

• libclimat: MPL-2.0, so the engine stays reusable outside a GPL program
• the application: GPL-3.0-or-later
• authored assets and documentation: CC-BY-SA-4.0
• bundled Inter: OFL-1.1; bundled GeoNames data: CC-BY 4.0

The repository is REUSE 3.3 compliant: every file carries an SPDX header, and reuse lint gates every commit. Every release carries an SBOM and a third-party licence bundle generated from that same metadata, plus a written offer for Qt's corresponding source.

Contributions are by DCO sign-off. There is no CLA.

Start with CONTRIBUTING.md. The short version: conventional commits, git commit -s, and if a change moves a golden image or a README image, the pull request has to say why the pixels moved.

The planning documents in docs/ are a frozen baseline, amended in place with dated corrections when the code contradicts them; docs/07-packaging.md §7.6 is a good example of what that looks like.