Weather#

Free: wttr.in (text) and Open-Meteo (JSON). No keys.

Default: one small request#

Prefer a short forecast to save tokens and latency:

• 1–2 days (typical “today / tomorrow / morgen”): https://wttr.in/PLACE?2&m — spaces → +. 2 = two-day forecast, m = metric.
• Full multi-day table only if the user asks for the week, several days, or ?2 is not enough: https://wttr.in/PLACE?T&m ( T = full terminal layout).

If the body looks like a real forecast → summarize and stop. No Open-Meteo unless wttr failed, error page, or you need JSON.

How to answer#

Chat, not a datasheet: short intro on how it feels, then compact day lines (date, °C, rain when it matters). No lat/long, WMO codes, or bold datasheet headings unless the user asked for technical detail.

wttr.in (curl / fetch)#

GoalExampleShort (default), 1–2 dayscurl -s "wttr.in/London?2&m"Full week-style tablecurl -s "wttr.in/London?T&m"One line nowcurl -s "wttr.in/London?format=3"Custom one-linercurl -s "wttr.in/London?format=%l:+%c+%t+%h+%w"

Tips: + for spaces; ?m / ?u units; ?1 today only; ?0 now only; airports wttr.in/JFK; PNG wttr.in/Berlin.png.

Open-Meteo (fallback)#

Hosts: geocoding-api.open-meteo.com, api.open-meteo.com only — not open-meteo.com HTML.

Flow (max 2 geocode + 1 forecast):

1. https://geocoding-api.open-meteo.com/v1/search?name=PLACE&count=10 (spaces as +)
2. If results missing/empty: one retry — shorter name + countryCode Pick the row whose admin3/ admin2/ admin1 matches the user phrase.
3. https://api.open-meteo.com/v1/forecast?latitude=LAT&longitude=LON&daily=temperature_2m_max,temperature_2m_min,precipitation_probability_max,weathercode&forecast_days=7&timezone=auto — extend forecast_days to 7–16 if they asked for more days.

Current only: curl -s "https://api.open-meteo.com/v1/forecast?latitude=51.5&longitude=-0.12&current_weather=true"

JSON: daily.time, temperature_2m_max / _min, precipitation_probability_max, weathercode — translate codes to plain words (see weather codes); never paste codes to the user unless asked.

When to use#

Named place — current weather or forecast.