Effective September 5, 2026 · applies to the Downstrike website and iOS app
Downstrike is a free lightning map made by two people, not a company. We want your data about as much as you want spam — which is to say, not at all. Here is everything, honestly.
If — and only if — you turn on storm warning notifications, we store two things on our server: your device's push token and your location rounded to about one kilometre. That's the minimum needed to check official National Weather Service warnings for your area while your phone is asleep. Turning alerts off deletes that record. Deleting the app orphans the token and the record is removed automatically. Nothing else is stored, and it is never sold, shared, or linked to your identity — we don't know who you are, and there are no accounts.
The website uses GoatCounter, a privacy-respecting counter that records page views without cookies or personal data. The iOS app contains no analytics at all.
To draw the map and weather, your device fetches data directly from: the Blitzortung.org lightning network, CARTO/OpenStreetMap (map tiles), Open-Meteo (wind), RainViewer (radar), OpenStreetMap Nominatim (one-time address lookup when you set home), and — in the app — Apple Weather (rain nowcast). These requests carry the usual technical minimum (your IP address, the area of map you're viewing) and are governed by those services' own policies. We add no identifiers to them.
Downstrike is for learning and storm-watching. It is not an emergency service — in dangerous weather, follow official guidance.
Email nzimmerman@gmail.com. If this policy ever changes, the date above changes with it.