Open-Meteo — Printing Press CLI

Prerequisites: Install the CLI

This skill drives the open-meteo-pp-cli binary. You must verify the CLI is installed before invoking any command from this skill. If it is missing, install it first:

1. Install via the Printing Press installer:

   npx -y @mvanhorn/printing-press install open-meteo --cli-only
   

2. Verify: open-meteo-pp-cli --version
3. Ensure $GOPATH/bin (or $HOME/go/bin) is on $PATH.

If the npx install fails (no Node, offline, etc.), fall back to a direct Go install (requires Go 1.23+):

go install github.com/mvanhorn/printing-press-library/library/other/open-meteo/cmd/open-meteo-pp-cli@latest

If --version reports "command not found" after install, the install step did not put the binary on $PATH. Do not proceed with skill commands until verification succeeds.

When to Use This CLI

Use this CLI for any weather, climate, or air-quality question that does not require a paid commercial agreement. It covers forecasts (16 days, multiple models), historicals (ERA5 from 1940), marine waves, air quality with pollen, river flood discharge, CMIP6 climate projections, and ensemble runs. Reach for the novel commands (compare, normals, weather-mix, panel, is-good-for) when the user is asking a decision or anomaly question rather than a raw-data question.

When Not to Use This CLI

Do not activate this CLI for requests that require creating, updating, deleting, publishing, commenting, upvoting, inviting, ordering, sending messages, booking, purchasing, or changing remote state. This printed CLI exposes read-only commands for inspection, export, sync, and analysis.

Unique Capabilities

These capabilities aren't available in any other tool for this API.

Local state that compounds

• forecast diff — See exactly what changed since the last forecast pull for this location — temperature deltas, new precipitation hours, weather-code shifts.

  Pick this when an agent needs to react to forecast changes (alerting, replanning) rather than to the current forecast itself.

  open-meteo-pp-cli forecast diff --place Seattle --json --select changes
  

• normals — Compute the 30-year (or user-specified) climate normal for any (location, day-of-year, variable) tuple.

  Use to ground a 'normal vs current' answer. Also useful for travel/timing recommendations across decades.

  open-meteo-pp-cli normals --place Seattle --month 7 --variable temperature_2m_max --years 30 --json
  

• accuracy — For any past date, compare what the model predicted (cached snapshot) against what actually happened (archive ground truth).

  Use to score forecast trust over time, or to debug a 'why did the forecast change?' question.

  open-meteo-pp-cli accuracy --place Seattle --date 2025-12-25 --variable temperature_2m_max --json
  

• weather-mix — Distribution of WMO weather conditions (% clear, % rain, % storms, etc.) over an arbitrary historical window for a place.

  Use for travel planning, climatology summaries, or 'how often does it rain in November?' questions.

  open-meteo-pp-cli weather-mix --place Seattle --past-days 30 --json
  

Cross-API joins

• compare — Compare today's weather (or any forecast hour) against the 30-year climate normal for that date and place.

  Use when a user asks 'is this weather unusual?' or 'how does this compare to historical?' — a single API call cannot answer.

  open-meteo-pp-cli compare --place Seattle --metric temperature_2m_mean --years 30 --json
  

• is-good-for — Verdict (GO / CAUTION / STOP) for surfing, skiing, hiking, running, biking based on combined forecast + marine + air-quality thresholds.

  Use when the user asks a decision question, not a data question. Saves the agent from synthesizing 3 endpoint calls into a verdict.

  open-meteo-pp-cli is-good-for surfing --place "Half Moon Bay, CA" --json
  

Agent-native plumbing

• panel — One-command snapshot panel for N locations side-by-side — batched in a single Open-Meteo call when possible.

  Use to compare conditions across locations in one shot; cheaper and faster than N separate calls.

  open-meteo-pp-cli panel --place Seattle,Berlin,Tokyo --current temperature_2m,wind_speed_10m,weather_code --json
  

Command Reference

air-quality — Air quality and pollen: PM2.5, PM10, ozone, NO2, SO2, CO, dust, pollens, EU/US AQI, UV.

• open-meteo-pp-cli air-quality — Air quality forecast and historical: pollutants, AQI, pollen, UV.

archive — Historical weather data (ERA5 reanalysis, 1940 to ~5 days ago). Same variable surface as forecast.

• open-meteo-pp-cli archive — Historical hourly/daily weather observations from ERA5 (1940 to ~5 days ago).

climate — CMIP6 climate change projections (1950-2050) under SSP scenarios.

• open-meteo-pp-cli climate — Daily CMIP6 climate projections for any (lat, lon) under SSP scenarios. Models include EC_Earth3P_HR, CMCC_CM2_VHR4,...

elevation — Digital elevation model lookup. Supports up to 100 coordinates per call.

• open-meteo-pp-cli elevation — Lookup elevation in meters for one or more coordinate pairs (up to 100).

ensemble — Ensemble forecasts (all model members) for uncertainty quantification.

• open-meteo-pp-cli ensemble — Hourly ensemble forecasts; returns all ensemble members so you can quantify uncertainty.

flood — River discharge / flood forecasts (GloFAS).

• open-meteo-pp-cli flood — Daily river discharge forecasts and historicals from GloFAS.

forecast — Weather forecast (up to 16 days). Free, no API key, hourly + daily + current resolution. Default model is best-available; pass --models for specific models (gfs_seamless, ecmwf_ifs025, dwd_icon, jma_seamless, metno_seamless, gem_seamless, meteofrance_arpege_world).

• open-meteo-pp-cli forecast — 7-16 day weather forecast for one or more coordinates. Pass comma-separated latitude/longitude for batch fetch.

geocode — Geocoding: search locations by name/postcode, or look up a location by ID.

• open-meteo-pp-cli geocode get — Look up a single location by its Open-Meteo geocoding ID.
• open-meteo-pp-cli geocode search — Search locations worldwide by name ('Berlin', 'Springfield, IL') or postcode.

marine — Marine weather: wave height, period, direction, swell components, sea-surface temperature.

• open-meteo-pp-cli marine — Marine forecast/historical: waves, swells, sea-surface temperature.

seasonal — Seasonal forecasts (up to 9 months) using NCEP CFSv2.

• open-meteo-pp-cli seasonal — 9-month seasonal forecast at six-hourly resolution. Default model is NCEP CFSv2.

Freshness Contract

This printed CLI owns bounded freshness only for registered store-backed read command paths. In --data-source auto mode, those paths check sync_state and may run a bounded refresh before reading local data. --data-source local never refreshes. --data-source live reads the API and does not mutate the local store. Set OPEN_METEO_NO_AUTO_REFRESH=1 to skip the freshness hook without changing source selection.

When JSON output uses the generated provenance envelope, freshness metadata appears at meta.freshness. Treat it as current-cache freshness for the covered command path, not a guarantee of complete historical backfill or API-specific enrichment.

Finding the right command

When you know what you want to do but not which command does it, ask the CLI directly:

open-meteo-pp-cli which "<capability in your own words>"

which resolves a natural-language capability query to the best matching command from this CLI's curated feature index. Exit code 0 means at least one match; exit code 2 means no confident match — fall back to --help or use a narrower query.

Recipes

Pick a slim forecast slice for an agent

open-meteo-pp-cli forecast --latitude 47.6062 --longitude -122.3321 --hourly temperature_2m,precipitation,weather_code --forecast-days 3 --json --select hourly.time,hourly.temperature_2m,hourly.weather_code

Use --select with dotted paths to narrow deeply nested time-series arrays. Open-Meteo responses can be tens of KB; this trims them to the columns you actually need.

Diff what changed in tomorrow's forecast

open-meteo-pp-cli forecast diff --place Seattle --json

Compares the current forecast against the cached prior pull for this place and emits only the changed hours.

Anomaly check: is this temperature unusual?

open-meteo-pp-cli compare --place Seattle --metric temperature_2m_mean --years 30 --json

Joins the 30-year ERA5 archive normal for the date and place against the current forecast.

Side-by-side panel for travel planning

open-meteo-pp-cli panel --place "Seattle,Berlin,Tokyo" --current temperature_2m,weather_code --json

Open-Meteo accepts comma-separated coords natively; the CLI batches the call and labels each result by place.

How often does it rain in October in Seattle?

open-meteo-pp-cli weather-mix --place Seattle --start-date 2024-10-01 --end-date 2024-10-31 --json

Aggregates archive hourly WMO codes into a category histogram (% clear / % rain / % storms / etc.).

Auth Setup

No authentication required.

Run open-meteo-pp-cli doctor to verify setup.

Agent Mode

Add --agent to any command. Expands to: --json --compact --no-input --no-color --yes.

• Pipeable — JSON on stdout, errors on stderr

• Filterable — --select keeps a subset of fields. Dotted paths descend into nested structures; arrays traverse element-wise. Critical for keeping context small on verbose APIs:

  open-meteo-pp-cli air-quality --agent --select id,name,status
  

• Previewable — --dry-run shows the request without sending

• Offline-friendly — sync/search commands can use the local SQLite store when available

• Non-interactive — never prompts, every input is a flag

• Read-only — do not use this CLI for create, update, delete, publish, comment, upvote, invite, order, send, or other mutating requests

Response envelope

Commands that read from the local store or the API wrap output in a provenance envelope:

{
  "meta": {"source": "live" | "local", "synced_at": "...", "reason": "..."},
  "results": <data>
}

Parse .results for data and .meta.source to know whether it's live or local. A human-readable N results (live) summary is printed to stderr only when stdout is a terminal — piped/agent consumers get pure JSON on stdout.

Agent Feedback

When you (or the agent) notice something off about this CLI, record it:

open-meteo-pp-cli feedback "the --since flag is inclusive but docs say exclusive"
open-meteo-pp-cli feedback --stdin < notes.txt
open-meteo-pp-cli feedback list --json --limit 10

Entries are stored locally at ~/.open-meteo-pp-cli/feedback.jsonl. They are never POSTed unless OPEN_METEO_FEEDBACK_ENDPOINT is set AND either --send is passed or OPEN_METEO_FEEDBACK_AUTO_SEND=true. Default behavior is local-only.

Write what surprised you, not a bug report. Short, specific, one line: that is the part that compounds.

Output Delivery

Every command accepts --deliver <sink>. The output goes to the named sink in addition to (or instead of) stdout, so agents can route command results without hand-piping. Three sinks are supported:

Sink	Effect
stdout	Default; write to stdout only
file:<path>	Atomically write output to <path> (tmp + rename)
webhook:<url>	POST the output body to the URL (application/json or application/x-ndjson when --compact)

Unknown schemes are refused with a structured error naming the supported set. Webhook failures return non-zero and log the URL + HTTP status on stderr.

Named Profiles

A profile is a saved set of flag values, reused across invocations. Use it when a scheduled agent calls the same command every run with the same configuration - HeyGen's "Beacon" pattern.

open-meteo-pp-cli profile save briefing --json
open-meteo-pp-cli --profile briefing air-quality
open-meteo-pp-cli profile list --json
open-meteo-pp-cli profile show briefing
open-meteo-pp-cli profile delete briefing --yes

Explicit flags always win over profile values; profile values win over defaults. agent-context lists all available profiles under available_profiles so introspecting agents discover them at runtime.

Exit Codes

Code	Meaning
0	Success
2	Usage error (wrong arguments)
3	Resource not found
5	API error (upstream issue)
7	Rate limited (wait and retry)
10	Config error

Argument Parsing

Parse $ARGUMENTS:

1. Empty, help, or --help → show open-meteo-pp-cli --help output
2. Starts with install → ends with mcp → MCP installation; otherwise → see Prerequisites above
3. Anything else → Direct Use (execute as CLI command with --agent)

MCP Server Installation

1. Install the MCP server:

   go install github.com/mvanhorn/printing-press-library/library/other/open-meteo/cmd/open-meteo-pp-mcp@latest
   

2. Register with Claude Code:

   claude mcp add open-meteo-pp-mcp -- open-meteo-pp-mcp
   

3. Verify: claude mcp list

Direct Use

1. Check if installed: which open-meteo-pp-cli If not found, offer to install (see Prerequisites at the top of this skill).
2. Match the user query to the best command from the Unique Capabilities and Command Reference above.
3. Execute with the --agent flag:

   open-meteo-pp-cli <command> [subcommand] [args] --agent
   

4. If ambiguous, drill into subcommand help: open-meteo-pp-cli <command> --help.