Solutions · Storms API

Tropical cyclones with cones, tracks and approach alerts

Every active tropical cyclone worldwide with its position, intensity, forecast cone and wind zones. Get a webhook when a storm forms, strengthens, comes within range of your port or asset, or dissipates.

Port and terminal hurricane preparedness
Fleet and cargo exposure alerts
Offshore operations planning

Get a free API key See the webhooks

Request

# Active systems with forecast cones, tracks and wind zones
curl "https://www.seasignals.com/v1/storms/active?geometry=false" \
  -H "Authorization: Bearer $SS_KEY"

Endpoints

Query it whenever you need it

GeoJSON responses with typed IDs, ISO 8601 times and units in every field name. Errors come back as {"error": {"code", "message"}}.

GET/v1/storms/activeActive systems with forecast cones, tracks and wind zones

GET/v1/ocean/pointExposure for a location: distance, bearing and whether it's in the cone (layers=storms)

Webhooks

Or let the events come to you

Subscribe a URL once and SeaSignals POSTs a signed JSON event whenever something changes. Checked every 30 minutes.

EVENTstorm.formedA new storm, at or above min_wind_kn

EVENTstorm.strengthenedIts category or alert level went up

EVENTstorm.approachingIt came within radius_nm of your point

EVENTstorm.dissipatedIt's no longer active

Filters

`lat`	Your point, needed for storm.approaching
`lon`
`radius_nm`	1 to 1,000 nm
`min_wind_kn`	Ignore weaker systems

Create a webhook

curl -X POST https://www.seasignals.com/v1/webhooks \
  -H "Authorization: Bearer $SS_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "url": "https://example.com/hooks/seasignals",
  "product": "storms",
  "events": [
    "storm.formed",
    "storm.strengthened",
    "storm.approaching",
    "storm.dissipated"
  ],
  "filters": {
    "lat": 29.7,
    "lon": -95.0,
    "radius_nm": 400,
    "min_wind_kn": 34
  }
}'

POST to your URL

{
  "id": "evt_3kV9q2mXw8rT1yLp0aZc4nB7",
  "type": "storm.approaching",
  "created_at": "2026-10-29T09:00:12Z",
  "webhook": "webhook:42",
  "data": {
    "type": "Feature",
    "id": "storm:1001234",
    "geometry": {
      "type": "Point",
      "coordinates": [
        -90.4,
        26.1
      ]
    },
    "properties": {
      "name": "Vance",
      "classification": "Hurricane",
      "category": 2,
      "max_wind_kn": 90,
      "movement_dir_deg": 315,
      "movement_speed_kn": 11,
      "distance_nm": 318.6,
      "bearing_deg": 128
    }
  }
}

Delivery

Signed, retried, logged

Signed: every request carries SeaSignals-Signature, an HMAC-SHA256 of the timestamp and body with your webhook secret.
Retried: anything but a 2xx within 10 seconds is retried after 1 min, 5 min, 30 min, 2 h and 6 h.
Logged: GET /v1/webhooks/{id} shows recent deliveries, and POST /v1/webhooks/{id}/test sends a test event.
Safe to retry: use the event id to ignore a delivery you've already handled.

// header: SeaSignals-Signature: t=1761729600,v1=5f2b…
const [t, v1] = header.split(",").map((p) => p.split("=")[1]);
const expected = crypto.createHmac("sha256", process.env.SS_WEBHOOK_SECRET)
  .update(`${t}.${rawBody}`).digest("hex");
const ok = crypto.timingSafeEqual(Buffer.from(v1), Buffer.from(expected))
  && Date.now() / 1000 - Number(t) < 300;

import hashlib, hmac, os, time

t, v1 = (part.split("=")[1] for part in header.split(","))
expected = hmac.new(os.environ["SS_WEBHOOK_SECRET"].encode(),
                    f"{t}.{raw_body}".encode(), hashlib.sha256).hexdigest()
ok = hmac.compare_digest(v1, expected) and time.time() - int(t) < 300

t, v1 = header.split(",").map { _1.split("=").last }
expected = OpenSSL::HMAC.hexdigest("SHA256", ENV["SS_WEBHOOK_SECRET"], "#{t}.#{raw_body}")
ok = ActiveSupport::SecurityUtils.secure_compare(v1, expected) && Time.now.to_i - t.to_i < 300

One key for every API

Vessels API

Live ship positions, tracks and area alerts

Port Calls API

Arrivals, departures and time in port

Port Delays API

Anchorage queues and overstays, port by port

Marine Life API

Whale, dolphin, shark and turtle sightings

Try the Storms API free

The free trial includes every API and up to 5 webhooks, 1,000 requests a day and 14 days of history.

Get a free API key API overview