Nws MCP Server

Real-time US weather data via National Weather Service API. Forecasts, alerts, and observations. The nws mcp server wraps that behind the Model Context Protocol, so an assistant can use it through 9 defined tools rather than through you.

What it actually does

• Declarative tool definitions — single file per tool, framework handles registration and validation
• Unified error handling across all tools
• Pluggable auth (none, jwt, oauth)
• Swappable storage backends: in-memory, filesystem, Supabase, Cloudflare KV/R2/D1
• Structured logging with optional OpenTelemetry tracing
• Runs locally (stdio/HTTP) or on Cloudflare Workers from the same codebase

Its toolset

Everything the assistant can do here goes through one of these:

• nws_get_forecast — 7-day or hourly forecast for coordinates. Resolves NWS grid internally
• nws_search_alerts — Active weather alerts filtered by area, point, zone, event, severity, urgency, certainty, and status
• nws_get_observations — Current conditions by coordinates (nearest station) or station ID
• nws_find_stations — Nearby observation stations sorted by distance with bearing
• nws_list_alert_types — All valid alert event type names for filter discovery
• nws_get_office_discussion — Latest narrative product (AFD, HWO, ZFP, SPS) from a Weather Forecast Office
• nws_get_zone_forecast — Text forecast periods for a public NWS forecast zone
• Prerequisites — The Prerequisites tool exposed by this server
• Installation — The Installation tool exposed by this server

Adding it to your client

Being a remote server, there is no local install. You register the endpoint with your client, authorise it once, and the tools appear.

Configuration

You will need 3 environment variables: MCP_TRANSPORT_TYPE, MCP_LOG_LEVEL, MCP_HTTP_HOST. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.

• Node.js v24+ or Bun v1.3+

When to reach for it

This sits in the cloud and infrastructure group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Nws's toolset — nws_get_forecast, nws_search_alerts, nws_get_observations and 6 more — is a fair guide to whether it matches your workflow. It is maintained by cyanheads; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Caveats

• Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
• With 9 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Nws.
• MCP clients confirm each tool call by default. Leave that on until you have watched what the nws mcp server does with a few real requests.