TWRadar: Taiwan Weather Radar

Radar and lightning, turned into a time machine: scrub back 72 hours and see where the rain came from. Alerts when lightning lands near you, or CWA tracks a new typhoon.

TWRadar turns Taiwan CWA open data into a radar time machine. Composite reflectivity is drawn straight onto Apple Maps. Drag the timeline back and watch where the rain came from, up to 72 hours. Optional alerts cover lightning near a chosen point, and new typhoons.

Native SwiftUI + MapKit, not a webview. Free, no ads, no account.

FEATURES • Radar overlay: nationwide composite reflectivity (~1.25 km), updated every 10 minutes. Opacity 15–100%; muted, standard, satellite or plain imagery basemaps. • 72-hour time machine: 6/12/24/36/48/60/72-hour ranges, frame steppers, 1× to 32× playback. Gaps in the archive are hatched, never papered over. • Lightning overlay: cloud-to-ground strikes (amber) and intra-cloud (cyan), updated every 5 minutes, on the same 72-hour timeline. New strikes flash as playback moves forward. • Typhoon tracks: when a cyclone is active, the map draws its past track and the CWA's published forecast, with the 70%-probability cone and a dot per fix coloured by intensity (Taiwan or Saffir–Simpson scale). Forecasts are the CWA's; we never compute our own. • Typhoon events: every storm we have recorded, with its whole path, free. Where we have the frames, Radar Pass Plus replays that passage's radar. • Lightning alerts: a notification when a strike lands near a point you pick, with the watched area drawn as a circle on the map. • Typhoon alerts: a notification when the CWA starts tracking a new typhoon or depression. Both are optional; no background location. • Tap-to-query dBZ: tap the map to read a cell's strength as a number (opt-in, in Settings). • 10 color palettes: the default Original scheme, a rain-only option, Standard NWS, and seven styled ramps (Chase, Sky, Broadcast, Vivid, Graphite, Neon, Retro). • Widgets: Home Screen small/medium/large showing the latest radar with lightning dots, plus Lock Screen widgets with peak dBZ and frame time. Each is configured on its own back: location, 5–80 km zoom or whole-Taiwan, map style, basemap and opacity. • Radar Loop, an animated widget: the last 1, 2, 3, 6 or 12 hours played as a loop at 1 to 4 frames per second, with the clock advancing and an optional progress bar. Needs Radar Pass Plus, and shows the latest frame without it. • Traditional Chinese / English interface, Taipei timestamps, 11 app icons.

DATA Taiwan Central Weather Administration open data: composite radar reflectivity (O-A0059-001, every 10 min), lightning (O-A0039-001, every 5 min), typhoon warnings (W-C0034-005). CWA serves only the latest frame; the 72-hour history is ours.

RADAR PASS The free tier shows the last 6 hours. Radar Pass Plus unlocks the full 72 hours, past typhoons' radar replay and Radar Loop's animation, as a monthly or yearly subscription (both with a free trial) or a one-time lifetime purchase. Typhoon tracks, every recorded storm's path and alerts stay free. No ads, no nag screens. The tip jar just buys us a drink; it unlocks nothing.

PRIVACY No accounts, no tracking, no third-party SDKs. Your location is read only when you tap the locate button, and is not sent to our servers.

Alerts are the one exception, and only if you turn them on: we store the point you pick (rounded to about 1 km before it is sent), the radius, your language, which alerts you enabled, and a notification token. Nothing else, not linked to any identity, deleted when you turn alerts off.

TWRadar is for general reference only. Do not rely on it for emergency response, aviation, marine or other safety-critical decisions; refer to official CWA bulletins.

Subscriptions: Monthly and Yearly Radar Pass Plus auto-renew, billed to your Apple Account at purchase confirmation. They renew automatically unless auto-renew is turned off at least 24 hours before the end of the current period. Lifetime is a one-time purchase and does not renew. Manage or cancel anytime in your App Store account settings. Privacy Policy: https://twradar.app/privacy.html Terms of Use: https://twradar.app/terms.html