Head to head · Weather forecasts · October 2026 research run

Meteosource Weather MCP vs Tomorrow.io Weather API

Tomorrow.io Weather API and Meteosource Weather MCP score within a point of each other on agent readiness, 51.5 (D) and 50.9 (D). Meteosource Weather MCP leads on security & auth, payments & pricing and maintenance & community. Both do weather forecasts.

Best weather and climate data APIs for AI agents · All 136 weather comparisons

Which one, for what

Meteosource Weather MCP D

Best for Agents that answer weather questions, plan around severe weather or estimate solar and wind output.

Ahead on

  • Security & auth, 42 against 34
  • Payments & pricing, 30 against 20
  • Maintenance & community, 70 against 27

Watch for

Plain API key, no OAuth

Tomorrow.io Weather API D

Best for Teams that need minute-level and route or polygon forecasts, alert webhooks and a hosted MCP server, and will buy through sales.

Ahead on

  • Reliability, 60 against 35
  • Transparency & trust, 53 against 32

Watch for

No public price for paid use. The plan table lists Free and Enterprise, the second by quote

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Maintenance & community Meteosource Weather MCP +43

Meteosource Weather MCP 70

Repository commit and tag v0.1.2 on 26 October 2026 (30). Three tags in 90 days (20). Repository issues not read (0). Official registry entry com.meteosource/weather (15). Small repository with server.json; server source not public (5 of 10). 30 + 20 + 0 + 15 + 5 = 70. Registry presence read from Anchor Terminal's own daily import of the official MCP registry (/api/v1/registry.json, 6 November 2026), not the registry's API.

Tomorrow.io Weather API 27

The newest release-note entry is October 2026, dated by month only, with the Bulk Timelines API, Density Altitude and new probability layers, a Dew Point Depression core layer and new aviation altitudes. A month-only entry is dated to its month, and October runs 4 to 34 days back, so it can't show a change within 30 days (20). The page was last updated on 13 October 2026, and the 8 October check saw July as the newest entry. That is one dated entry since 6 August, not three (0). Release notes with five entries in thirteen months, a status page updated several times a week, and a help centre that answered 403 on 8 October, not re-read. The community repository on GitHub was last pushed in April 2021, per the 8 October check (7 of 15). No official SDK, and no registry presence read in this run (0). No packages to assess (0). 20 + 0 + 7 + 0 + 0 = 27.

Reliability Tomorrow.io Weather API +25

Meteosource Weather MCP 35

status.meteosource.com wasn't reachable (0). No history (5). Daily call quotas per plan, and the README's plans-and-limits section (15). Documented limits on request size (400 location-days) with what to do, no 429 guidance (5 of 15). No SLA found (0). Version 0.1.2, not labelled beta (10). 0 + 5 + 15 + 5 + 0 + 10 = 35.

Tomorrow.io Weather API 60

Graded as a hosted service. Status page at status.tomorrow.io on Atlassian Statuspage, with 22 components on its history page, among them Timeline API, Historical API, Alerts API and Gale AI (20). The history pages list 37 incidents between 7 August and 3 November 2026, most of them stale or degraded data for a region or product. Two are labelled major. Recently created insights and monitors produced stale data on 12 August (12:46 to 16:30 UTC, Insights API and Alerts API), and Next Gen FOCUS regional forecast data was missing for some regions on 14 August (15:15 to 01:00 UTC, CONUS unaffected). Each hit one product or a set of regions, so both read as partial and the record is minor incidents only (20). The rate-limit page says limits are per hour and day by plan and gives no numbers (0 of 15). 429 is documented for a passed limit, and the errors page gives Retry-After and 'wait and retry' for 503, with no idempotency keys or safe-retry guidance on the location, insight and alert writes, so Retry-After alone (10). The pricing page lists Custom SLAs on Enterprise and its title claims 99.9% uptime, but no SLA document was found, and a listed SLA nobody could read gives 0 (0). Version 4 of the REST API is generally available (10). 20 + 20 + 0 + 10 + 0 + 10 = 60.

Transparency & trust Tomorrow.io Weather API +21

Meteosource Weather MCP 32

The repository is MIT (copyright 2026 Meteosource) but holds docs and the registry manifest rather than the server; terms and privacy URLs weren't found (10 of 30). The MCP page says keys aren't stored in full and caches are per key (10 of 30). No deprecation policy (0). Subprocessors not found (5 of 20). 10 + 10 + 0 + 5 = 25.

Tomorrow.io Weather API 53

Closed service under subscription terms at www.tomorrow.io/legal/terms-of-service/. robots.txt on www.tomorrow.io closes /legal/ to every reader, as our policy reader recorded on 8 October, so the 8 October readings of the terms, the product privacy policy and the data sources page are struck. The terms are published but unread on a host that refuses us, which keeps the licence line at 15, as for linkedin-marketing-api and figma-mcp. The plans page footer names The Tomorrow Companies Inc. in Boston (15 of 30). Data handling rested only on the struck privacy reading, and no docs page states retention or deletion, so the line is 0, as struck evidence is for x-mcp and hexis (0 of 30). The versioning policy promises notice far in advance of a breaking change with no period, and the docs mark the best timestep as deprecated without a date (6 of 20). Subprocessors and data locations rested only on the struck privacy and data sources readings (0 of 20). 15 + 0 + 6 + 0 = 21.

Payments & pricing Meteosource Weather MCP +10

Meteosource Weather MCP 30

No machine payment protocol (0). Plan prices with daily call quotas, public (10). Free plan with 400 calls a day, no card (20). A person signs up in a browser for the key (0). 0 + 10 + 20 + 0 = 30.

Tomorrow.io Weather API 20

No x402, MPP or L402 in the docs or the OpenAPI file. A 402 response exists for spent tokens, with no payment protocol behind it (0). The plan table is public and lists what Free includes, but Enterprise is by quote and token prices for the Historical API aren't published (5 of 20). A free plan with a 5-day forecast, 24 hours of history, one monitored location and one alert. The pages read name no card or payment step, but the signup form is a script-rendered app we couldn't read (15 of 20). A person signs up in a browser. The MCP OAuth flow registers clients by API but still needs a human login (0). 0 + 5 + 15 + 0 = 20.

Security & auth Meteosource Weather MCP +8

Meteosource Weather MCP 42

One API key per account in a header, never in the URL (20 of 30). All tools are reads (10 of 20). Weather data only, no third-party text (10). No audit log (0). No security programme found (2 of 20). Keys travel to the hosted server, which says it doesn't store them in full. 20 + 10 + 10 + 0 + 2 = 42.

Tomorrow.io Weather API 34

The docs state that API keys carry full privileges, with one default key on the dashboard and more keys created by an account manager. The key may travel as an apikey query parameter, which the OpenAPI file declares as the scheme, or as a header. The MCP endpoint also advertises OAuth with dynamic client registration, PKCE (S256) and one scope, mcp:read, in its live metadata, which the MCP docs page doesn't mention (12 of 30, after the 10-point deduction for a secret in the URL). Weather calls only read, the OAuth scope is read-only, and the key can also create, change and delete locations, insights and alerts with no confirmation step (10 of 20). Responses are mostly numeric fields. Gale AI returns generated text and the feeds carry third-party event text, with no guidance on treating it as untrusted (8 of 15). An X-Correlation-ID on every response and an Activity section in the dashboard for webhooks. No per-call log was found in the docs (4 of 15). No security.txt (404 on www on 4 November 2026, and on the apex and api hosts per the 8 October check), and no disclosure policy, bounty or certification found on the pages read or by a site search (0 of 20). 12 + 10 + 8 + 4 + 0 = 34.

Score by category

CategoryWeight this runMeteosource Weather MCPTomorrow.io Weather APIEdge
Reliability16%203560Tomorrow.io Weather API +25
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27275Tomorrow.io Weather API +3
Agent ergonomics13%16.27573Meteosource Weather MCP +2
Security & auth14%17.54234Meteosource Weather MCP +8
Payments & pricing10%12.53020Meteosource Weather MCP +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87027Meteosource Weather MCP +43
Transparency & trust7%8.83253Tomorrow.io Weather API +21
Negative events≤1500
TotalD 50.9/100D 51.5/100

Facts side by side

FactMeteosource Weather MCPTomorrow.io Weather API
KindMCP serverHTTP API
VendorMeteosourceThe Tomorrow Companies Inc.
Hosted endpointhttps://mcp.meteosource.com/mcphttps://api.tomorrow.io/v4
TransportsStreamable HTTPHTTP
AuthAPI keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceProprietary service. The repository's MIT licence covers its docs and manifestProprietary service under Tomorrow.io's subscription terms
Tools exposed711
Read-only variant documentednono
llms.txtnoyes
MCP registrycom.meteosource/weathernot listed
Last releasenone2026-10-13
Terms last updatedno document linkedcouldn't be read
Privacy policy last updatedno document linkedcouldn't be read
Customer content may train modelsnot read yetcouldn't be read
Terms restrict automated accessnot read yetcouldn't be read
Terms restrict benchmarkingnot read yetcouldn't be read
Terms or service can change without noticenot read yetcouldn't be read
Arbitration or class-action waivernot read yetcouldn't be read

How the scores have moved

Verdicts

Meteosource Weather MCP

Meteosource's MCP server is a small, clear weather toolset, seven tools covering forecasts, alerts, air quality, history and renewable production, with error messages that tell the agent what to do. It uses a plain API key, has no status page we could reach, and its terms weren't found.

Tomorrow.io Weather API

A public OpenAPI 3.1 file, Markdown docs with llms.txt and a hosted MCP server with 11 tools suit agents, and a free plan exists. Paid prices are by quote, the docs give no numeric rate limits, no SLA document or security.txt was found, and the status page lists 37 incidents in 90 days, mostly stale or degraded regional data.

Before you call either

Meteosource Weather MCP

  1. Call search_places first to resolve a location
  2. Split history requests over 400 location-days into shorter ranges
  3. Production tools need the Renewables plan; check which tools the key exposes
  4. Send the key in a header, never in a URL

Tomorrow.io Weather API

  1. Send the key in the apikey header, not the query string, so it stays out of URLs and logs
  2. Request only the fields and timesteps needed on POST /timelines. Free plans cover 24 hours back and 5 days ahead at 1h and 1d
  3. Split archive requests. POST /historical takes at most 31 days per call and deducts tokens, 1 for a point and 10 for a polygon
  4. Treat code 401001 as a missing or bad key and stop retrying
  5. On 429 back off without a hint. Retry-After is documented only for 503
  6. Expect stale or degraded data for some regions during incidents. status.tomorrow.io has components per API

Questions

Which is better for AI agents, Meteosource Weather MCP or Tomorrow.io Weather API?

Tomorrow.io Weather API and Meteosource Weather MCP score within a point of each other on agent readiness, 51.5 (D) and 50.9 (D). Meteosource Weather MCP leads on security & auth, payments & pricing and maintenance & community.

Do Meteosource Weather MCP and Tomorrow.io Weather API need an API key?

Meteosource Weather MCP needs an API key. Tomorrow.io Weather API takes an API key or an OAuth sign-in.

Can an agent call Meteosource Weather MCP and Tomorrow.io Weather API without installing anything?

Yes. Meteosource Weather MCP has a hosted endpoint at https://mcp.meteosource.com/mcp and Tomorrow.io Weather API at https://api.tomorrow.io/v4.

Other comparisons with Meteosource Weather MCP or Tomorrow.io Weather API

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