Meteomatics Weather API vs Stormglass API

Meteomatics Weather API

A public OpenAPI file, a hosted MCP server whose nine tools are all marked read-only, a published SLA with compensation and ISO 27001 certification suit company use. Access needs a sales contract, with no public price, free tier or self-serve signup found, no status page, and REST calls that authenticate with a username and password.

Stormglass API

A read-only weather and marine API with about 70 hourly parameters, per-source values from named national models, tide data and ERA5 history from 2014. No OpenAPI file, status page, SDK or security page was found, the free plan allows 10 requests a day, and the docs and FAQ disagree on the status code for a spent quota.

Meteomatics Weather API

1. Ask the account owner for credentials first. There is no signup, and both the REST API and the MCP server need a Meteomatics account with API access
2. Build REST URLs as validdatetime/parameters/location/format, for example 2026-10-08T00:00:00Z/t_2m:C/52.52,13.40/json. Parameter names carry their unit after a colon
3. Keep each query to 10 locations and 10 parameters unless the contract says otherwise, and use POST when a GET URL passes 2,000 characters
4. Send credentials or the token in the Authorization header. Avoid the documented access_token query parameter, which puts the token in URLs and logs
5. Read /user_stats_json before a large job. It reports queries sent and the contract's limits, and 429 means a limit is spent
6. Treat reserved values such as -888 and -999 as invalid or missing data, and shrink the request when a 408 arrives after the 300-second timeout

Stormglass API

1. Send the key as Authorization: KEY with no Bearer prefix. A missing or wrong key returns 403 with {"errors":{"key":"API key is invalid"}}
2. Always pass source=sg or a short source list on /weather/point. The default is every source, which multiplies the size of each hourly record
3. Treat 402 as a spent daily quota, not a billing failure, and stop until the next day. Read meta.requestCount against meta.dailyQuota on each response
4. Use /historical/point for past dates, at most 10 days a call and nothing newer than about 7 days. /weather/point looks back 14 days only
5. Send and read all times in UTC. Tide sea levels are relative to the chosen datum (MSL by default) and are not water depth