Radar reflectivity

Tiles of Central Weather Administration (CWA) composite radar reflectivity (echo intensity, dBZ). Coverage is 115°E–126.5°E and 18°N–29°N, on a 0.0125° grid. About 7 days are kept. The interval follows CWA releases. Use the list. Use the tiles for rainfall-echo animation and live weather maps.

Shared rules (coordinates, caching, attribution, and full map examples) are in Map tiles.

Data license

Attribution · Commercial use OK
AttributionData: Central Weather Administration (CWA), ExpTech Studio (exptech.dev)

Upstream terms

Central Weather Administration (CWA): CWA's own data terms (such as the Open Government Data License) also apply; CWA's official releases take precedence.

Where to show it, examples and commercial-use requests: Data licensing and attribution.

Authentication

No API Token is required.

Available times

GEThttps://api.core-tnn1.exptech.dev/api/v2/tiles/radar/list

Commercial OK

ServerTNN-1

Request

curl --compressed "https://api.core-tnn1.exptech.dev/api/v2/tiles/radar/list"

const res = await fetch("https://api.core-tnn1.exptech.dev/api/v2/tiles/radar/list");
if (!res.ok) throw new Error(`HTTP ${res.status}`);
const data = await res.json();
console.log(data);

import requests

res = requests.get(
    "https://api.core-tnn1.exptech.dev/api/v2/tiles/radar/list",
    timeout=10,
)
res.raise_for_status()
print(res.json())

Response

200500

Success (an empty array [ ] when there is no data). Gzip-compressed when the client supports it

[
  1794641400,
  600,
  600,
  600
]

Server error (plain-text error message)text/plain

Try it

Response fields

The response is a delta-encoded array of integers, oldest first, in Unix seconds. See Map tiles for how to decode it.

Field	Type	Description
`[0]`	`integer`	Time of the oldest entry, in Unix seconds.
`[i]（i ≥ 1）`	`integer`	Gap from the previous entry, in seconds. Add these up to get each time.

Tiles

GEThttps://static.core-tnn1.exptech.dev/api/v2/tiles/radar/{time}/{z}/{x}/{y}.webp

Commercial OK

ServerTNN-1

Path parameters

timeintegerRequired
Unix seconds. Must be a value from the list (an exact match; the server does not pick the nearest entry).
zintegerRequired
Zoom level, 3–12. Outside that range the response is a 1 × 1 transparent GIF.
xintegerRequired
XYZ tile column.
yintegerRequired
XYZ tile row (north to south).

Request

curl -o output.webp "https://static.core-tnn1.exptech.dev/api/v2/tiles/radar/<time>/<z>/<x>/<y>.webp"

const res = await fetch("https://static.core-tnn1.exptech.dev/api/v2/tiles/radar/<time>/<z>/<x>/<y>.webp");
if (!res.ok) throw new Error(`HTTP ${res.status}`);
const blob = await res.blob();

import requests

res = requests.get(
    "https://static.core-tnn1.exptech.dev/api/v2/tiles/radar/<time>/<z>/<x>/<y>.webp",
    timeout=10,
)
res.raise_for_status()
with open("output.webp", "wb") as f:
    f.write(res.content)

Response

200304400500

image/webp, 256 × 256, lossless, transparent background. Only cells with echo (dBZ > 0) are drawn. If z is outside 3–12, the tile is outside coverage, or there is no echo in range, the response is a 1 × 1 transparent GIF (image/gif)binary image/webp

If-None-Match matches the ETag. No contentNo response body

time is not an integer

bad time

That time does not exist, or the server errored. The body is a single newlineNo response body

Try it

Color scale

After the fractional part of dBZ is dropped, each integer maps to one color (0–65 dBZ; above 65 uses the color for 65). The main stops:

dBZ	Color	Notes
0–14	`#00FFFF` → `#0000FF`	Cyan to blue, darker with each dBZ
15–25	`#00FF00` → `#009600`	Green, darker with each dBZ
26–29	`#33AB00` → `#CCEA00`	Yellow-green
30–35	`#FFFF00` → `#FFC800`	Yellow
36–44	`#FFB800` → `#FF1800`	Orange
45–55	`#FF0000` → `#960000`	Red, darker with each dBZ
56–59	`#AB0033` → `#EA00CC`	Magenta
60–65	`#FF00FF` → `#9600FF`	Magenta to purple

Notes

A missing time returns 500, which is a different status from 404. The body is a single newline. Use only times from the list. Times older than about 7 days drop off the list, and the tiles for them are gone.
The time must match exactly. time is Unix seconds. Do not use milliseconds.
A z, x, or y that is not an integer does not return 400. It is treated as 0. Check the values yourself.
Set minzoom: 3 and maxzoom: 12 in the map library for zoom levels you do not need. Above 12, scale up level-12 tiles.
The bytes for a tile URL are fixed, so cache them on the client for a long time. The response has no Cache-Control, but it has an ETag for conditional requests.
The same list path is also available on the tile host, but it is cached for about an hour. Use the list host above for the latest time.
On the map, credit the source with the suggested attribution in Data license.