Environment Canada IDF Curve Update - Version 3.30 Release Adds Stations and Extends Data Records

Environment and Climate Change Canada has released the Version 3.30 of the Engineering Climate Datasets: https://collaboration.cmc.ec.gc.ca/cmc/climate/Engineer_Climate/IDF/

The number of stations and the length of average station record has increased with 276 updated stations, 38 new stations and 9 joined stations. This brings the total number of stations to 714, a significant increase relative to the time I started working.

The following table and charts illustrate how the number of stations and station-years of record have increased over time.

The number of "station-years" of data in the current data set (some data up to 2021) is 66% greater than the approximate number of station years in earlier data up to 1990. That is good to see.

Average record length is now up to 26.2 years, and the average 'last year' of data is just past 2007 (there are 3 stations that stopped in the 1940's, which brings the average last year down).


This chart shows how the number of stations and station-years of data have increased over the past several decades. Note that the years on the x-axis for 3.1, 3.2, and 3.3 are the respective release years (2019, 2021 and 2023), and not the newest data year included.

There have been suggestions that the number of stations has declined, adversely affecting the ability to assess changes in extreme rainfall intensities - see discussion in an earlier post https://www.cityfloodmap.com/2020/06/do-we-have-enough-climate-stations-in.html

Mekis et. al noted that the number "Manual" stations has declined as shown in the following chart - that can reflect the change in technology to automated stations that replaced manual stations (remember those analog strip charts?). The number of stations with IDF data has increased though, from only 532 stations in the 1990 data set to 714 now - a 34% increase. Those increases in station numbers are shown against the decrease in manual stations below. 

The average record length has been increasing overall as well (see table above), resulting in more reliable trend data today. Note that the addition of many new stations tends to pull the average record length down as shorter record length stations are factored in. Overall, more data is better and the new station records can extend over time.