Climate Change Impact Adaptation Planning
Climate change impacts are worsening globally and locally here in Hamilton. These impacts could include but are not limited to more shoreline and escarpment erosion causing infrastructure damage, more frequent and severe storms, increase number of extreme heat events, and more precipitation leading to flooding. Climate Change Impact Adaptation Planning will help to minimize the impacts on our residents and businesses, especially those most vulnerable to these impacts, to help reduce recovery time and costs.
In order to create Hamilton’s Climate Change Impact Adaptation Plan the City of Hamilton is asking all stakeholders who are interested to participate. There will be a series of engagement activities to identify and prioritize projects, and inform implementation plans with the goal of increasing the resiliency of our City and our community.
Project background
The City of Hamilton is working with ICLEI Canada through their Building Adaptive Resilient Communities (BARC) framework. This program offers a comprehensive way to respond to the impacts of climate change, develop and implement an adaptation plan, and protect the people, property, and prosperity of our community.
City staff consulted with community stakeholders in a series of workshops in 2016 and 2017 about which projected impacts were of the greatest concern, creating a prioritized ranking. It has become clear recently that some of those rankings may be out of date (e.g. Flooding in Lake Ontario was not prioritized highly at that time, but since then the waterfront has flooded multiple times).
City staff will consult with organizations and the community to update the vulnerability and risk assessment scoring as a first step to complete Hamilton’s Climate Impact Adaptation Plan. Following this, we will undertake workshops, surveys, and other forms of community engagement to develop projects and tools to reduce the consequences of climate change on our communities. Please sign up for our email list and visit this page regularly to be informed of our engagement opportunities.
City of Hamilton Future Climate Projections
A summary of climate data for the City of Hamilton (as defined by the Climate Atlas of Canada it summarizes data from 24 climate models). The purpose of this report is to inform how the climate is projected to change from now until predominantly the 2080s, and to provide direction for the assessment of climate risk and eventual adaptation actions for both municipalities.
Hamilton Climate Science Full Report (PDF, 936 KB)
Hamilton Climate Science Infographic (PDF, 2 MB)


Description: Annual Mean Temperature and Seasonal Mean Temperatures
Annual Mean Temperature (Thermometer showing rising mercury). Mean temperatures are projected to increase annually and in every season.
| Time Period | Temperature |
|---|---|
| 2051-2080 | 12.5˚C |
| 2021-2050 | 10.4˚C |
| Annual Baseline | 8.3˚C |
Seasonal Mean Temperatures (A snowflake, flower, sun, and leaf, denoting the seasons of winter, spring, summer, and fall respectively)
| Season | Time Period | Temperature |
|---|---|---|
| Winter (December to February) | 2051-2080 | 0.8˚C |
| 2021-2050 | -1.6˚C | |
| Baseline | -3.9˚C | |
| Spring (March to May | 2051-2080 | 10.4˚C |
| 2021-2050 | 8.5˚C | |
| Baseline | 6.7˚C | |
| Summer (June to August) | 2051-2080 | 24.5˚C |
| 2021-2050 | 22.3˚C | |
| Baseline | 20.1˚C | |
| Fall (September to November) | 2051-2080 | 14.3˚C |
| 2021-2050 | 12.3˚C | |
| Baseline | 10.1˚C |
Description: Heat Waves, Tropical Nights and Temperature Extremes
Heatwaves (A sun and rays, paired with a set of rippling lines; “3.8” and “8.4 days” separated by a right-facing arrow).
Heatwaves are defined as three or more days in a row which reach or exceed 30˚C. Sustained heat exposure can have significant impact on the health of individuals including heat stroke and even death.
In Hamilton, the length of an average heatwave is expected to increase from 3.8 to 8.4 days by the year 2080.
Tropical Nights (A first-aid kit and a room fan)
Typically, cooler nights can mitigate exposure to extreme heat, however, an increased number of tropical nights eliminates the possibility for relief and magnifies health risks, especially to vulnerable populations such as infants, older adults, and those who work outdoors.
Night-time temperatures above 20˚C are expected to see a fivefold increase by 2080.
Temperature Extremes (Bars in two sets of three, decreasing in length in the first set, increasing in length in the second set).
More hot days, fewer cold days.
| Days at or Above 30˚C | |
|---|---|
| Number of Days | Time Period |
| 63.3 | 2080s |
| 37.2 | 2050s |
| 16.1 | Baseline |
(*retaining order in which information appears in the graphic and table consistent. Hence ‘Time Period’ appearing on the right-hand column here.)
| Days at or Below - 15˚C | |
|---|---|
| Number of Days | Time Period |
| 1.3 | 2080s |
| 5.3 | 2050s |
| 13.8 | Baseline |
Description: Freeze-thaw Cycles and Annual Mean Precipitation
Freeze-thaw Cycles (Three circles decreasing in size from left to right).
A decrease in freeze-thaw days is expected.
| Time Period | Number of Days |
|---|---|
| Baseline | 66.4 |
| 2050s | 58.2 |
| 2080s | 48.9 |
Annual Mean Precipitation (A ruler with marks along its left side and a small hole in the bottom right)
Increased precipitation can cause flooding, damage to infrastructure, and decreases to water quality.
| Time Period | Precipitation Quantity |
|---|---|
| 2051-2080 | 923mm |
| 2021-2050 | 898mm |
| Baseline | 844mm |
Seasonal Mean Precipitation (A snowflake, flower, sun, and leaf, denoting the seasons of winter, spring, summer, and fall respectively)
| Season | Time Period | Precipitation Quantity |
|---|---|---|
| Winter (December to February) | 2051-2080 | 221mm |
| 2021-2050 | 207mm | |
| Baseline | 187mm | |
| Spring (March to May | 2051-2080 | 254mm |
| 2021-2050 | 240mm | |
| Baseline | 217mm | |
| Summer (June to August) | 2051-2080 | 217mm |
| 2021-2050 | 219mm | |
| Baseline | 217mm | |
| Fall (September to November) | 2051-2080 | 232mm |
| 2021-2050 | 232mm | |
| Baseline | 223mm |
Description: Annual Mean Temperature and Seasonal Mean Temperatures
Precipitation Events (Three side-by-side images of rain clouds; three images of raindrops set side-by-side)
Precipitation events in general are projected to become more intense and more extreme.
| Intensity | Precipitation will fall at a faster rate (mm/h) |
|---|---|
| Duration | Shorter storms will have an increasingly high intensity. |
| Frequency | Return periods of heavy storms will shorten, meaning increased frequency. |
For instance, 100-year rainfall events will see precipitation rates increase substantially from baseline in Hamilton. 5-minute downpour rates shown.
| Time Period | Precipitation Rate |
|---|---|
| Baseline | 189.76 mm/h |
| 2050 | 214 mm/h |
| 2080 | 209.35 mm/h |


