About ShadeDial

Why it exists

I have a family, an RV, and a long history of eating lunch in direct sunlight.

Every trip went the same way. Pull into the site, read the sun, put the awning out. An hour later the sun had moved and we were eating in it again. Move the chairs — sun finds us. Move the table — sun finds us. At some point you stop calling it bad luck and start suspecting the sun has taken a personal interest in you.

You’d have thought I was Dracula, the way I hunted shade. I am not. I just wanted to finish a sandwich before it went warm.

The maddening part is that the whole thing was decided months earlier, at booking, by a number I picked off a map. Site C20 or site C24 — one of them has trees to the west and one doesn’t, and nothing on the reservation page says which. Reviews tell you “some sites are shady.” Booking systems tell you “shaded / partial / none” without telling you when. Neither is any help with thirty seconds on the clock on launch morning.

So I worked it out. Site by site. Then I put it on the internet, in case anyone else has been chased around a picnic table by the sun.

How it works

1. 1. Find every site. Campsite coordinates and attributes come from the park services themselves — 6,624 individual numbered sites across 33 campgrounds in 21 national parks.
2. 2. Build a horizon for each one. For every site we look outward in 180 directions and record how high the sky is blocked — by canyon walls and ridgelines up to 16 km away, and by tree canopy nearby.
3. 3. Run the sun across it. The sun’s path is stepped through the day in 15-minute intervals and checked against that horizon. What comes out is when the sun reaches each site and when it leaves — the shade window you actually plan a day around.

Data sources

• Campsite positions & attributes— Recreation.gov campsite records (US) and Parks Canada open data via OpenStreetMap (Canada). Ratings shown as “park-rated” come straight from Recreation.gov, not from us.
• Terrain — Mapzen / AWS Open Data terrain tiles (bare-earth elevation).
• Tree heights — ETH Zurich Global Canopy Height model, 10 m resolution, satellite-derived, 2020.
• Sun position — standard astronomical formulas (NOAA), accurate to a fraction of a degree.
• Imagery — © Esri, Maxar, Earthstar Geographics.

Where this is wrong

Worth reading before you trust a number. We would rather tell you the limits than have you find them at the campsite.

• Trees are the weak link. The canopy data is 10 m resolution, which cannot resolve a campground — pads, loop roads and trees are interleaved below that scale. We tested how much this matters by re-running everything with a different assumption about how much clearing surrounds a pad: at forested campgrounds it moved the daily totals by hours. Rankings held up better than absolute figures, so trust “shadier than that one” more than “exactly six hours”.
• Terrain is solid.Canyon walls and ridgelines don’t move, and that part of the model is reliable. Desert and canyon campgrounds are our most trustworthy pages for that reason.
• The canopy data predates the fires. It was captured in 2020. Campgrounds hit by the 2024 Jasper wildfire are computed from terrain alone and carry a warning on the page — those figures are an upper bound on sun, so they will never promise you shade that burned.
• Times are rounded to the half hour and written as “around”, because the inputs underneath don’t support finer than that.
• Clear sky only. Weather is not included, and figures are computed for the 15th of each month from June to September.

Independence

ShadeDial is an independent planning tool, built and run by one person — me. It is not affiliated with the National Park Service, Parks Canada, Recreation.gov, or any booking provider, and it earns no commission on anything you book. Nobody pays for placement here, and nobody can.

Common questions

Is this an official park service site?

No. ShadeDial is independent and not affiliated with the National Park Service, Parks Canada, Recreation.gov, or any booking provider. Reservations always happen on the official sites — we just link to them.

Can I book a campsite here?

No, and we don’t want to. ShadeDial is for the part that happens before booking: working out which site numbers you actually want. The booking button sends you to the official reservation system.

Is it free? What's the catch?

Free, no account, no ads, no affiliate commission — the reservation systems don’t pay any. It costs about $25 a year in domain fees and some hosting, which is cheap enough to keep running while we find out whether anyone wants it.

How accurate is it, really?

The sun’s position is exact. The terrain is good. Trees are the weak link — see the accuracy section below, which spells out exactly where the model struggles. Treat every figure as an estimate and verify with the park.

My campground isn't here. Will you add it?

Search for it anyway — every search that finds nothing is recorded, and that list is how we decide what to add next. Or email us and say which one.

I camped somewhere and the shade was wrong.

Please tell us. Every site page has a thumbs up/down, and that feedback is the only way we can find the sites we’ve got wrong. It is genuinely the most useful thing anyone can send.

Contact

Corrections, missing campgrounds, bug reports, or anything else. It comes to me and I read all of it.

The single most useful thing you can send: a campground and site number where the shade didn’t match what we said.