Wind Calendar

Generate windsurfing calendar feeds from weather forecasts

Subscribe to filtered wind forecasts for your preferred spots and get notifications when conditions are good.

Launch App →

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Features

• Smart filtering - Only get events when wind speed, daylight, and wave conditions match your preferences
• Multiple forecast models - Choose from GFS, ICON, GDPS, or IFS-HRES weather models
• Session grouping - Automatically merges consecutive forecast hours into surf sessions
• Calendar integration - Subscribe via standard ICS/webcal protocol (works with all major calendar apps)
• Israeli surf spots - Pre-configured for Beit Yanai, Bat Galim, Herzliya, and More

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Quick Start

Web Interface (Recommended)
Visit wind-calendar.vercel.app to configure your preferences and get a subscription link.

Direct API
Construct a URL and subscribe by replacing https:// with webcal://:

webcal://wind-calendar.vercel.app/api/calendar?location=herzliya&windMin=14&model=om_gfs

Paste the webcal:// URL into your calendar app (Apple Calendar, Google Calendar, Outlook, etc.) to subscribe.

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For AI Agents

This project provides a public API for wind forecast calendar feeds. AI agents can discover this functionality via the SKILL file, located at skills/wind-calendar/SKILL.md.

To install the skill, use the following command:

npx skills add https://github.com/or-yam/wind-calendar --skill wind-calendar

Quick Example:

https://wind-calendar.vercel.app/api/calendar?location=herzliya&windMin=14

Returns an ICS calendar feed with windsurfing/kitesurfing sessions filtered by wind conditions.

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How It Works

1. Fetch - Pulls wind and wave forecast data from Open-Meteo (primary) or Windguru (fallback)
2. Filter - Removes forecasts outside your wind speed range, during darkness, or below minimum wave height
3. Group - Merges adjacent hourly forecasts into sessions (max 3-hour gap between points)
4. Generate - Creates ICS calendar events with session details (wind range, gusts, direction, waves)

Filtering Logic

• Wind speed must be within windMin to windMax range (note: gusts are NOT capped by windMax)
• Forecast must be during daylight hours (timezone-aware using spot's IANA timezone)
• Wave height must be >= waveHeightMin (if wave data available)
• Grouped sessions must be >= minSessionHours duration

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Config Options

API Query Parameters

Parameter	Type	Default	Description
location	string	beit-yanai	One of: beit-yanai, bat-galim, herzliya, tel-aviv
windMin	number	14	Minimum wind speed in knots (>= 0)
windMax	number	35	Maximum wind speed in knots (<= 200)
minSessionHours	number	2	Minimum session duration in hours (0-24)
model	string, number	om_gfs	Forecast model (see below)

Example API Request

curl "https://wind-calendar.vercel.app/api/calendar?location=beit-yanai&windMin=14&windMax=35&minSessionHours=2&model=om_gfs"

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Forecast Models

Open-Meteo (Recommended)

Primary provider using open-source weather data from government agencies:

Model ID	Model Name	Description
om_gfs	GFS 13 km	NOAA Global Forecast System (default, reliable)
om_icon	ICON 13 km	DWD German model (excellent for Europe/Med)
om_gdps	GDPS 15 km	Canadian Meteorological Centre global model
om_ifs	IFS-HRES 9 km	ECMWF high-resolution (often most accurate)

Data provided by Open-Meteo.com (CC-BY 4.0 license) using public weather model data from NOAA, DWD, CMC, and ECMWF.
Fallback: Automatically falls back to Windguru if Open-Meteo is unavailable.

Windguru (Legacy)

Legacy provider supported for backward compatibility:

Model ID	Model Name	Open-Meteo Equivalent
3	GFS 13 km	om_gfs
45	ICON 13 km	om_icon
59	GDPS 15 km	om_gdps
117	IFS-HRES 9 km	om_ifs

Local Development

Prerequisites:

• Node.js, pnpm

Setup:

pnpm install

Run locally:

# Frontend only (port 5173)
pnpm dev

# Fullstack (Vite + API functions)
pnpm dev:api

# Check everything (format + lint + typecheck + test)
pnpm check

Tooling:

This project uses oxc (oxlint + oxfmt) for linting and formatting - not ESLint or Prettier.

# Format code
pnpm fmt

# Lint code
pnpm lint
pnpm lint:fix

# Run tests
pnpm test