Air quality data
We combine two sources in a collector that runs every hour. The static site also fetches the same sources when it builds as a fallback; in the browser, the latest validated collector snapshot updates the displayed readings and rankings without waiting for another site build.
Environment and Climate Change Canada (AQHI). Canada's official Air Quality Health Index from the government monitoring network, via the MSC GeoMet open-data API. We show a town's AQHI when there is a monitoring station within 40 km. AQHI runs 1-10+: 1-3 is low health risk, 4-6 moderate, 7-10 high, above 10 very high.
Open-Meteo PM2.5 (modelled). Many smaller destinations have no monitoring station, so for every location we also use gridded fine-particle (PM2.5) estimates from Open-Meteo's air quality API, which is built on the Copernicus CAMS atmospheric model. Modelled values can differ from what a monitor on the ground would read, especially near active fires, but they are consistent across locations, which is what a ranking needs.
Exact-location enrichment. When you choose your exact spot, WeatherAPI can add current temperature, cloud, wind, UV and local air data. In the United States, AirNow can add a nearby preliminary observation reported by federal, state, local or tribal agencies. We show that observation separately from the Open-Meteo model so the two are not confused. If either optional service is unavailable, the map and rankings continue to work.
Weather map. Temperature and precipitation overlays come from WeatherAPI's weather-map tiles. The “sky battery” is only a friendly brightness proxy calculated from current cloud cover. It is not a vitamin D dose or medical guidance.
Ranking
For each origin city we list every tracked place within roughly a 3-hour drive, sorted by current PM2.5 (lowest first), with drive time as the tie-breaker. We deliberately rank by measured air, not by reputation: a town that is usually clear can be the smokiest place on the list during the wrong wind, and the ranking will reflect that.
The cigarette equivalence
To make a PM2.5 number mean something, we translate it into a familiar one: cigarettes. The figure on each city page is how much fine-particle pollution you would breathe standingoutside for 12 hours today, expressed as a cigarette-smoking equivalent.
22 µg/m³ of PM2.5 for 24 hours ≈ 1 cigarette
This comes from Berkeley Earth's analysis, which found that breathing 22 µg/m³ of PM2.5 over a day carries roughly the health impact of smoking one cigarette. So for a 12-hour day outside we compute(PM2.5 ÷ 22) × (12 ÷ 24) cigarettes, and each destination shows the same figure so you can see how many cigarettes a drive would spare you.
This is an equivalence for the health impact of fine particles, not literal smoking. You are not inhaling tobacco, tar or nicotine. The comparison only lines up the long-term harm of the particulate matter in wildfire smoke against a yardstick most people already understand. It is a rough guide, most useful for comparing one place with another on the same day.
Drive times
When we have a cached road route for a city-to-town pair, we show its real driving time. Otherwise we estimate: straight-line distance adjusted by a typical road-winding factor (×1.3) at an average trip speed of 85 km/h. Geography, borders, ferries and road networks can make actual travel substantially different. Always check a routing app before leaving. During major fire events some highways close.
Lodging links
Hotel and rental links go to third-party booking sites' search results for each town. Some links may earn us a commission at no cost to you; commissions never affect rankings, which are computed purely from air-quality data. Selected dates are passed to those searches, but availability is only confirmed by the provider. ToClearSkies does not currently claim that a room is available before you open the provider.
Limits
Air quality during wildfire events changes hour to hour. This site is a planning tool, not a health service. For health decisions follow Environment Canada's advisories, AirNow, and your local public-health authority. If every destination on your city's page shows poor air, the best getaway may be staying indoors with filtration.