Ontario Environmental Health Dashboard
30 indicators. One province. Tracked close to home.
The same four elements — Land, Air, Water, and Fire — mapped to the issues affecting Ontario specifically: the Great Lakes, southern Ontario's farmland and wetlands, and the air we breathe in the GTA. Click any tile for the full picture.
30Ontario indicators tracked
2Rated Critical
27Trending worse
6Categories covered
How we score severity
A transparent, repeatable 0–100 scale.
Severity:Critical ≥75Serious 50–74Moderate 25–49Watch <25
AtmosphereSerious
Summer smog & ground-level ozone
Southern Ontario regularly exceeds Canadian air quality standards on hot summer days
Severity 62/100▲ Worsening
AtmosphereSerious
Urban heat island effect (GTA)
Downtown Toronto can run 5–12°C hotter than surrounding rural areas on summer nights
Severity 66/100▲ Worsening
AtmosphereSerious
Wildfire smoke events reaching southern Ontario
Multiple air quality advisories per season linked to northern wildfire smoke, up sharply since 2021
Severity 70/100▲ Worsening
AtmosphereSerious
Ontario greenhouse gas emissions trend
Transportation is Ontario's largest emissions source, and provincial emissions have plateaued rather than fallen
Severity 55/100▲ Worsening
AtmosphereModerate
Ontario electricity grid emissions intensity
Ontario's grid is roughly 90% non-emitting, thanks largely to nuclear and hydro
Severity 28/100▼ Improving
Great Lakes & FreshwaterCritical
Lake Erie harmful algal blooms
Western Lake Erie sees recurring large-scale algal blooms most summers
Severity 78/100▲ Worsening
Great Lakes & FreshwaterSerious
Great Lakes water level volatility
Record highs and record lows recorded within the same decade on several lakes
Severity 58/100▲ Worsening
Great Lakes & FreshwaterSerious
Microplastic pollution in the Great Lakes
Among the highest microplastic concentrations recorded in any freshwater system globally
Severity 64/100▲ Worsening
Great Lakes & FreshwaterSerious
Invasive species in the Great Lakes
Dozens of aquatic invasive species established, led by zebra and quagga mussels
Severity 69/100▲ Worsening
Great Lakes & FreshwaterSerious
PFAS ('forever chemicals') in drinking water sources
PFAS detected in a growing number of Ontario municipal and private water supplies
Severity 60/100▲ Worsening
LandCritical
Southern Ontario wetland loss
More than 72% of southern Ontario's original wetlands have been lost
Severity 75/100▲ Worsening
LandSerious
Greenbelt & farmland development pressure
Ontario has repeatedly proposed and reconsidered opening protected Greenbelt land to development
Severity 59/100▲ Worsening
LandSerious
Farmland loss to urban sprawl
Ontario loses farmland to development faster than most other provinces
Severity 63/100▲ Worsening
LandSerious
Emerald ash borer & forest pest damage
Emerald ash borer has killed the majority of ash trees across infested regions of Ontario
Severity 57/100▲ Worsening
LandSerious
Road salt contamination of urban waterways
Chloride levels in many GTA streams now regularly exceed guidelines for aquatic life
Severity 54/100▲ Worsening
BiodiversitySerious
Moose population decline (northern Ontario)
Moose populations have declined significantly across parts of northern Ontario in recent decades
Severity 61/100▲ Worsening
BiodiversitySerious
Species at risk in Ontario
Ontario's Species at Risk list has grown to several hundred listed species
Severity 67/100▲ Worsening
BiodiversitySerious
Pollinator decline in Ontario
Ontario beekeepers have reported elevated winter colony losses in multiple recent years
Severity 56/100▲ Worsening
BiodiversityModerate
Chronic Wasting Disease risk to deer populations
Chronic Wasting Disease has been detected approaching Ontario's borders and in isolated cases within the province
Severity 48/100▲ Worsening
BiodiversitySerious
Phragmites (invasive reed) spread
Invasive phragmites has spread rapidly along Ontario roadsides, wetlands, and shorelines
Severity 52/100▲ Worsening
Human HealthSerious
Air-quality-linked respiratory illness
Air pollution linked to thousands of premature deaths in Ontario annually
Severity 64/100▲ Worsening
Human HealthSerious
Extreme heat & heat-related illness
Toronto and other Ontario cities are issuing more heat warnings each summer
Severity 60/100▲ Worsening
Human HealthSerious
Lyme disease range expansion
Tick populations carrying Lyme disease have expanded into most of southern and central Ontario
Severity 58/100▲ Worsening
Human HealthSerious
Boil-water advisories (esp. First Nations communities)
Multiple long-term drinking water advisories remain in effect in First Nations communities in Ontario
Severity 72/100▲ Worsening
Human HealthSerious
Basement & urban flooding risk
Insurance claims for water damage have risen sharply across Ontario municipalities
Severity 65/100▲ Worsening
ResourcesSerious
Ontario landfill capacity
Many southern Ontario landfills are projected to reach capacity within the next 10–15 years
Severity 66/100▲ Worsening
ResourcesSerious
Ontario recycling & diversion rate
Ontario's residential waste diversion rate remains below many other provinces
Severity 54/100● Stable
ResourcesSerious
Building energy retrofit gap
The large majority of Ontario's building stock predates modern energy efficiency standards
Severity 50/100▲ Worsening
ResourcesModerate
EV charging infrastructure gap
Public charging infrastructure growth is lagging behind Ontario's rising electric vehicle adoption
Severity 46/100▼ Improving
ResourcesModerate
Aggregate (gravel & mining) extraction pressure
Aggregate extraction applications continue to expand into environmentally sensitive areas of southern Ontario
Severity 49/100▲ Worsening