YEARLY Thunderstorm Days EXTENDED - WINNIPEG (since 1870s)
NOTE: Thunderstorm data before 1953 on this page are unofficial, and for curiosity purposes only. Trends in thunderstorm days seen may be the result of both climate changes as well as changes in observation standards. For instance, the full hourly observing program did not start until 1947. Prior to 1947, some thunderstorm events may be missed as there wasn't necessarily someone watching the weather 24/7.
The data before 1953 going back to the 1880s were retrieved from old summaries published by various Government of Canada departments back in the day. The Hathi Trust Digital Library was the primary source to find the publications starting in the 1910s (see Winnipeg metadata page for links). Otherwise, Google Books was used to retrieve data from the following publications: Monthly Weather Review Meteorological Service Dominion of Canada, and the Report from the Meteorological Service of Canada to the Dominion of Canada. Publications prior to 1901 are more difficult to find, explaining some data voids in the graphs.
In the 1870s, thunderstorm observations are from James Stewart (possibly in the Lord Roberts / Riverview area), who reported his data to the Winnipeg Free Press every year (therefore, not St John's College).
The data before 1953 going back to the 1880s were retrieved from old summaries published by various Government of Canada departments back in the day. The Hathi Trust Digital Library was the primary source to find the publications starting in the 1910s (see Winnipeg metadata page for links). Otherwise, Google Books was used to retrieve data from the following publications: Monthly Weather Review Meteorological Service Dominion of Canada, and the Report from the Meteorological Service of Canada to the Dominion of Canada. Publications prior to 1901 are more difficult to find, explaining some data voids in the graphs.
In the 1870s, thunderstorm observations are from James Stewart (possibly in the Lord Roberts / Riverview area), who reported his data to the Winnipeg Free Press every year (therefore, not St John's College).