Weather

Weather

Fetch and display current weather and forecasts — no API key required.

Decision flow

1. Identify the location from the user's request.
   • If the user says "here", "my location", or gives no city, ask for the city name.
   • URL-encode spaces: New+York, São+Paulo.
   • Airport codes work: JFK, LHR, NRT.
2. Detect the platform (or infer from context):
   • Linux / macOS / Git Bash → curl
   • Windows PowerShell → curl.exe (bare curl maps to Invoke-WebRequest and may fail)
3. Choose the format based on what the user wants:
   • Quick one-liner → format=3
   • More detail (humidity, wind) → custom format string
   • Full 3-day forecast → ?T flag
   • Structured data / calculations → Open-Meteo JSON (see below)

wttr.in — primary source

One-line summary (default for most queries)

# Linux / macOS
curl -fsSL "https://wttr.in/London?format=3"
# → London: ⛅️ +8°C

# Windows PowerShell
curl.exe -s "https://wttr.in/London?format=3"

Compact with humidity and wind

# Linux / macOS
curl -fsSL "https://wttr.in/London?format=%l:+%c+%t+%h+%w"
# → London: ⛅️ +8°C 71% ↙5km/h

# Windows PowerShell
curl.exe -s "https://wttr.in/London?format=%l:+%c+%t+%h+%w"

Full 3-day forecast (plain text, renders as a table)

curl -fsSL "https://wttr.in/London?T"          # Linux
curl.exe -s  "https://wttr.in/London?T"         # Windows

Current conditions only (no forecast days)

curl -fsSL "https://wttr.in/London?0"           # Linux
curl.exe -s  "https://wttr.in/London?0"          # Windows

Units

Append to the URL query string:

Format codes (for custom format= strings)

Open-Meteo — fallback for structured/JSON use

Use when the user wants data for calculations, comparisons, or programmatic output. Requires coordinates (latitude/longitude).

# Linux / macOS
curl -fsSL "https://api.open-meteo.com/v1/forecast?latitude=51.5&longitude=-0.12&current_weather=true"

# Windows PowerShell (cleanest for JSON)
Invoke-RestMethod -Uri "https://api.open-meteo.com/v1/forecast?latitude=51.5&longitude=-0.12&current_weather=true"

Returns JSON: temperature, windspeed, winddirection, weathercode, time.

Add &hourly=temperature_2m,precipitation for hourly data, or &daily=temperature_2m_max,precipitation_sum for daily summaries. Docs: https://open-meteo.com/en/docs

WMO weather code → plain language

Presenting results to the user

• Short query ("what's the weather in Paris?"): run format=3, then restate in a natural sentence — "It's currently ⛅ 12°C in Paris."
• Forecast request ("3-day forecast for Tokyo"): use the ?T flag and display the text table directly — it's already nicely formatted.
• JSON / Open-Meteo: translate weathercode to plain language; don't dump raw JSON at the user.
• Fetch failure: if the city isn't found or the request times out, try an alternate spelling or ask the user to confirm the location.