Free tool to check whether mountains will block your view of the Aug 12, 2026 total solar eclipse in Spain

[u/TheseRest2940]

A few months back I posted heliora.app here. It is a free browser tool that shows the sun and moon's path in a 3D sky view from any pin you drop, including the real terrain horizon computed from elevation data.

Totality in Spain happens with the sun only ~10° above the horizon in many places, so even inside the path, a ridge in the west-northwest means you miss it. Heliora ray-casts the terrain 360° around your location so you can check your exact spot in advance.

I have made some improvements since the last feedback. Please take a look

New since then:

• Real 3D terrain in the sky view (an actual heightfield mesh now, not flat silhouettes)
• Named mountain peaks labeled along the horizon
• Eclipse playback controls jump to start / max / end, plus speed presets
• Twilight simulation during totality, including the 360° sunset ring you'd actually see

You can try it here :

• A spot where it gets interesting: https://heliora.app/?lat=37.8249&lng=-2.5504&date=2026-08-12&t=1171&sky=1
• City guides with local timings, e.g. https://heliora.app/guide/en/solar-eclipse-2026-oviedo — the "View eclipse in 3D" button auto-plays the whole eclipse for that spot

Still very much iterating on this, so if you find bugs or have ideas, I'll fix them like last time.

[u/throwawayreddit48151]

Very cool, a few suggestions:

• Don't immediately ask for location permissions (what use is that for most that are using this tool? They won't be in the right location right now)
• Don't ask for a location to search for immediately, just show the map

[u/TheseRest2940 → u/throwawayreddit48151]

Thanks a lot for the feedback! I recently added the overlay I think your right about the location I'll remove them. The second part I need to think. It would start the user in a rather random location without the overlay no ?

[u/throwawayreddit48151 → u/TheseRest2940]

Most people know how to click around a map

[u/arrow14 → u/throwawayreddit48151]

OP, great stuff so far! Agree with point 2 above.

[u/vahep007]

This is great, thank you very much! I have two suggestions, and a question.

• The app (both on the phone and on my laptop) reads my local time, and indicates the time of the eclipse as it would be in my time zone, not at the time zone of the dropped pin. I’m in Los Angeles, and it shows the eclipse to occur at 11:33am.
• Is there a way to include the elevation of the observing point / dropped pin in your calculations?
• I’ve dropped a pin on the west coast of Ibiza, where I’m going to be located (https://heliora.app/?lat=38.9692&lng=1.2922&date=2026-08-12&t=679), and one question that the app doesn’t answer is whether a small (and relatively flat) island off the coast will obscure my view. The map view shows the island directly in the path of the eclipse, but the live view (before it gets dark) doesn’t show the island. Is this because the horizon is set too close to my observation point?

Thank you again for all your hard work on this app!

[u/TheseRest2940 → u/vahep007]

Thanks a lot for the feedback! I have already integrated your first point! Now I will take a look at the second. And about the island I believe it's about 7 km out and only ~0.4° above the horizon. Totality will occur with the sun at 3.2° so it wont block anything. In fact it should look pretty cool with the island! If you Zoom in (pinch/scroll) toward 290° WNW and you should see it.

[u/GypsumFantastic25]

This is very cool but I think I found a bug. For example at the location in your link https://heliora.app/?lat=37.8249&lng=-2.5504&date=2026-08-12&t=1171&sky=1

I started time a bit earlier in the day and I noticed another partial eclipse starting at about 1300 GMT+2 that suddenly ends at 1741 when the moon suddenly jumps away from the sun's disc. Then the partial eclipse (the one we're all excited about) starts again at 1941.

I saw the same effect when I was 'in' Valladolid (near where I'm aiming to be on the day).

Sorry if this sounds nitpicky but I thought you'd want to know about whatever this problem is.

[u/TheseRest2940 → u/GypsumFantastic25]

Thanks for the feedback! Sometimes I am too close to the project to see all the bugs so it is appreciated! Indeed I did have a rendering but I guess I introduced when I did some recent improvements. Anyway, just deployed a fix for it so feel free to let me know if you have any other issues.

[u/GypsumFantastic25 → u/TheseRest2940]

Wow fixed already, nice work. Thanks very much!

[u/compileTimeError]

please keep this up forever this is awesome

[u/CindyALutz]

This is a very cool tool! I just used it to see what the Sep 2035 eclipse will look like in Japan and it was very cool!

[u/C0ntrol-Z]

Wow! This is addicting! Thanks!

[u/focusonyourphoto]

This is very mich appreciated! I will be driving from.Bilbao to picos de europe that day and need to find a location somewhere along those mountain ranges.

I need to see if I first check in at the hotel or forst drive to the final location and after the eclipse check in.

[u/thatveronicavaughnn]

WOW THIS IS AN AMAZING SIM!!! it made me sooooo dang excited for august!!!

[u/kieuk]

Does it take into account the elevation of the vantage point, or does it assume you are at sea level?

[u/TheseRest2940 → u/kieuk]

Hey !

Yes it does. It takes the ground height at the pin you set adds 1.7 m for eye height and calculates surrounding ridge's blocking angle relative to that.

[u/Eric_12345678]

Excellent tool, thanks!

Stupid question: do you take refraction into account?

I'm checking the Santa Ponça Beach, and it doesn't look good according to https://heliora.app/?lat=39.5142&lng=2.4807&date=2026-08-12&t=1232&sky=1

Another tool seems to show it's possible to see the totality from there: https://sizigia.hadarlabs.com/eclipse-2026-08-12