Precipitation Monitoring

Precipitation samples are collected on a weekly basis from monitoring equipment in Southampton, PEI. The precipitation that is collected includes rainwater and snow, often called wet precipitation. The main objective of the sampling is to monitor changes of precipitation quality over time, specifically pH.  Acid rain can be measured using the pH of wet precipitation, with normal rain having a pH of about 5.6. Acid rain usually has a pH of between 4.2 and 4.4.*     

* source:

What is the pH of precipitation on PEI?

The pH of the collected samples varies from year to yearn with data being collected since 1982. The PEI Air Monitoring Data Hub includes a Precipitation Monitoring dashboard that graphs the changes from 2004 to present, with the graph being updated annually. The annual average pH value has increased from 4.8 in 2004 to 6.1 in 2022.

What other data are available?

Although pH is the focus of the precipitation monitoring, several other parameters are also collected and analyzed. The full dataset from 2004 to present is available for download in the province's Open Data Portal

Published date: 
August 3, 2023
Environment, Energy and Climate Action

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Department of Environment, Energy and Climate Action
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PO Box 2000
Charlottetown, PE C1A 7N8

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