A Chrome extension that adds weather forecasts directly into Google Calendar's day headers.
- Weather badges on every day header (icon, high/low temps)
- Works across all views: week, day, month, schedule, and custom
- Click a badge for a detailed overlay with precipitation, wind, and UV index
- Toggle visibility from the calendar's view dropdown menu
- Configurable location (city search, geolocation, or manual coordinates)
- Configurable units (Fahrenheit/Celsius, mph/km/h, inches/mm)
- 16-day forecast + 7 days of past weather
- Free weather data from Open-Meteo — no API key required
- Clone this repo
- Open
chrome://extensionsin Chrome - Enable Developer mode (top right)
- Click Load unpacked and select the repo folder
- Click the extension icon and set your location
Coming soon
- After installing, click the extension icon in the toolbar
- Search for a city, use your current location, or enter coordinates manually
- Choose your preferred units
- Weather badges will appear in your Google Calendar headers
Toggle weather on/off from the calendar's view dropdown (the same menu where you switch between Week, Month, etc.).
Weather data is provided by the Open-Meteo API, a free and open-source weather API. No API key or account is required.
Weather icons are from Basmilius Meteocons.
This is a standard Chrome Manifest V3 extension with no build step:
├── manifest.json # Extension manifest
├── background.js # Service worker (API fetching, caching)
├── content.js # Content script (badge injection)
├── content.css # Content script styles
├── popup.html/js/css # Settings popup
├── icons/ # Extension icons
└── weather-icons/ # Weather condition SVGs
To develop:
- Load the extension unpacked in Chrome
- Edit files
- Click the reload button on
chrome://extensionsto pick up changes - Refresh Google Calendar
MIT