British Columbia

These graphics show just how much record-breaking rain hit southern B.C. recently

B.C. has declared a state of emergency in the wake of devastating floods caused by record rainfall last weekend in the southern part of the province. These graphics illustrate the scope of what is being called a once-in-a-century storm.

20 rainfall records were set Sunday as a massive storm rolled through the region

An RCMP helicopter surveys homes and farms in the community of Sumas Prairie during flooding in Abbotsford, B.C., on Tuesday. (Ben Nelms/CBC)

B.C. has declared a state of emergency and a mammoth cleanup effort is getting underway in the wake of devastating floods in the southern part of the province.

The flooding — which has displaced thousands of people and damaged property, transportation networks and other infrastructure — was caused by record rainfall last weekend, with many officials calling the storm that hit the province a once-in-a-century event.

But just how rare was the amount of rain that fell? Below are a few graphics that illustrate the scope of the rainfall.

How much rain fell?

Twenty-four B.C. communities received more than 100 millimetres of rain from Saturday to Monday, according to a preliminary Environment Canada weather summary issued at 5:41 a.m. PT Tuesday. This article is based on that information; a summary with finalized storm totals came later Tuesday with updated figures.

The town of Hope led the way with 252 millimetres over that time period.

By way of comparison, the average rainfall for the entire month of November in Hope is 344 millimetres.

Coquihalla Summit, Agassiz, Chilliwack and Squamish also received more than 200 millimetres of rainfall from Saturday to Monday.

Where were records broken?

According to Environment Canada, preliminary rainfall records were set in 20 areas on Sunday.

Calculations "point toward a widespread one-in-50 year event, with many locations seeing a one-in-100 year event. That is putting into context how anomalous this event was," Armel Castellan, a meteorologist at Environment Canada, told a news conference Tuesday.

The Hope area smashed its previous record by nearly 140 mm, seeing 174 mm of rainfall on Sunday. Its previous record, set in 2018, was 34.7 mm.

Meanwhile, the 127.3 mm received by Agassiz on Sunday broke a rainfall record that had stood for 125 years. Its previous record of 36.3 mm was set in 1896.

Hover your mouse over the following graphic to see other areas where records were broken.

How unusual was the rainfall for this time of year?

To address this question, CBC News looked at the rainfall measured at the Vancouver Harbour station.

Specifically, the combined rainfall total on Sunday and Monday (Nov. 14 and 15) was compared to the combined rainfall totals of Nov. 14 and 15 in previous years going back to 1980, using historical data available from Environment Canada.

As the following graphic shows, the station measured 115.8 mm of rainfall over those two days this week, the highest amount in at least 41 years.

The previous high for Nov. 14 and 15 in that period was 101.2 mm measured in 1983.

In comparison, the average rainfall for those two days from 1980 to 2021 was a mere 19.93 mm.


  • A previous version of this story used rainfall totals for the North Vancouver Wharves station. It has since been replaced with Vancouver Harbour station, which is maintained and standardized.
    Jan 31, 2022 12:25 PM PT

With files from The Canadian Press