Pirate Weather vs Visual Crossing Weather API

Pirate Weather

Named model sources and a documented priority order for every field. No SLA, and the terms call it best effort.

Visual Crossing Weather API

History from 1970, current conditions and a 15-day forecast from one endpoint. Key only in the query string on the REST API.

Pirate Weather

1. Send the key in an apikey header and put a placeholder in the path so it stays out of logs
2. Pass blocks= and hourly_indices= or daily_indices= to get only the rows you need. The default payload is large
3. Ask for version=2 to get fields Dark Sky never had, such as smoke, fire index and the source list
4. Point historical requests at timemachine.pirateweather.net with a UNIX timestamp after the coordinate
5. Watch Ratelimit-Remaining. The cap is monthly, so a runaway loop can spend it in a day

Visual Crossing Weather API

1. Always pass include= and elements=. A bare call returns days, hours and current for every element and burns records
2. Count records before a backfill. Hourly data is 24 records a day, so a year for one place is 8,760
3. Pass unitGroup=metric. The default is US units
4. Use the MCP server with X-VC-API-Key rather than pasting the key into a URL
5. Keep to one request at a time on Free and Professional. A second concurrent job returns 429