Ontario Night Sky — Stargazing & Aurora Forecast

Ontario Night Sky (also known as Clear Night Planner) is a decision-first stargazing and aurora forecast for 12 dark-sky sites across Ontario, Canada. We combine Open-Meteo weather, US-AQI wildfire-smoke data, moon phase & altitude, astronomical twilight and Bortle-scale darkness into a single tonight score (0–100) plus a 48-hour hourly forecast. The full app is a JavaScript-powered React site — please enable JavaScript to see the live forecast.

Dark-sky sites we cover

Torrance Barrens Dark-Sky Preserve — Muskoka, Bortle 3. Ontario's first permanent dark-sky preserve, ~2h from Toronto.
Killarney Provincial Park — Georgian Bay, Bortle 2. Designated dark-sky preserve on the La Cloche range.
Lake Superior north shore — Algoma, Bortle 2. Among the darkest skies in Ontario.
Algonquin Provincial Park — Nipissing, Bortle 3. Vast wilderness with widely accessible dark skies.
North Frontenac Dark-Sky Preserve — Frontenac, Bortle 2. Municipally-protected site with a public observing pad near Plevna.
Bruce Peninsula National Park — Bruce, Bortle 3. Designated dark-sky preserve with Lake Huron horizons.
Point Pelee National Park — Essex, Bortle 4. Southernmost mainland Canada.
Gordon's Park, Manitoulin Island — Bortle 2. RASC-designated preserve with on-site observing fields.
Quetico Provincial Park — Rainy River, Bortle 1. Wilderness canoe park; exceptionally dark.
Pukaskwa National Park — Algoma, Bortle 2. Rugged Lake Superior coastline.
Binbrook Conservation Area — Hamilton, Bortle 5. Popular and accessible Hamilton-area site.
Long Sault Conservation Area — Durham, Bortle 4. Toronto-area observing spot.

Tonight's verdict (build-time snapshot)

For a real-time-data view that does not require JavaScript, see the prerendered tonight pages. Each page contains the current verdict (Excellent / Good / Fair / Poor / No-go), the longest clear observing window during astronomical night, moon phase & illumination, and mean cloud cover, refreshed at every deploy.

How the tonight score works

The score blends seven hourly metrics — cloud cover, transparency, seeing, astronomical darkness (sun + moon), wildfire smoke (US-AQI / PM2.5), humidity and temperature — weighted by your observing mode (visual, deep-sky, planetary or astrophoto), then adds a Bortle-aware darkness bonus so darker sites score higher for deep-sky targets.

Open data feeds for AI agents and researchers

All editorial content is freely citable with a link back to the app. Machine-readable mirrors:

/llms.txt — curated index (llmstxt.org spec)
/llms-full.txt — full editorial content for RAG / embedding
/sites/index.json — structured list of all 12 sites
/ai.json — top-level AI feed manifest
/sitemap.xml — XML sitemap
Live MCP server (Streamable HTTP, public, no auth): https://koohxdehsweadgdegrly.supabase.co/functions/v1/mcp
Live REST forecast API (one-shot JSON for agents/embeds): https://koohxdehsweadgdegrly.supabase.co/functions/v1/forecast?site=<id>