The reconstruction of Kelowna’s climate record from 1951 to today, comes from five weather stations (see map Figure 1): 

1) Old Glenmore, station ID 1123930. January 1, 1951 to September 30, 1962.

2) Southeast Kelowna, station ID 1123980. January 19, 1951 to December 31, 1969.

3) Quail Ridge, station ID 11239R0. January 1, 1994 to December 31, 2013.

4) Airport, station IDs 1123970, 1123995, and 1123939. January 1, 1969 to today.

5) University of British Columbia Okanagan Campus, station ID 1123996. January 1, 2014 to today.

        In this analysis, the airport weather station was set as the primary station for Kelowna. Data from the other Kelowna stations used to complete the climate record were adjusted for micro-climatic differences using statistical techniques relative to the airport climate record.

Annual Changes

        Displayed in Figure 2 is Kelowna’s annual average mean temperature from 1951 to 2025. Annual average mean temperature is calculated by adding up all of the daily mean temperatures and dividing that value by the number of days in the year (either 365 or 366). Daily mean temperature is calculated by adding the daily maximum temperature and the daily minumum temperature and dividing that value by 2. According to the best-fit line, annual average mean temperature has increased by 2.01°C over the the 75-year record.

        

        Figure 3 shows annual average maximum and minimum temperature from 1951 to 2025.  Both temperature measures show a stead increase over the period. Annual average maximum temperatures are increasing at rate of 0.09°C per decade faster than annual average maximum temperatures.

       

        Figure 4 shows annual precipitation from 1951 to 2025.  Annual precipitation is the total amount of rain and snow that fell during the calendar year. The graph indicates that annual precipitation was on average higher between 1980 and 2005. There appears to be a trend of declining annual precipitation since 2005.

Seasonal Changes

        Figure 5 shows spring (March, April, and May) average mean temperatures from 1951 to 2025. Spring temperatures have increase by 2.12°C over this 75 year period.

        Figure 6 shows summer (June, July, and August) average mean temperatures from 1951 to 2025. Over this 75-year period, summer temperatures have increase by 1.72°C according to the best-fit regression line.

        Figure 7 shows fall (September, October, and November) average mean temperatures from 1951 to 2025. Fall temperatures have increase by 1.61°C over this 75 year period according to the best-fit regression line.

        Figure 8 shows winter (December - previous year, January, and February) average mean temperatures from 1952 to 2026. Over this 75-year period, winter temperatures have increase by 2.57°C according to the best-fit regression line.

Monthly Changes

        Figure 9 shows the historical change in average monthly minimum temperatures for three periods: 1951 to 1980, 1981 to 2010, and 2011 to 2025. Between 1951 to 1980 and 2011 to 2025, average monthly minimum temperatures rose between 0.28 to 4.10°C. The greatest rise in temperature occurred in the January, March, June, July, August, September, November, and December.

        Figure 10 displays the historical change in average monthly maximum temperatures for three periods: 1951 to 1980, 1981 to 2010, and 2011 to 2025. Between 1951 to 1980 and 2011 to 2025, average monthly maximum temperatures rose for all months between 0.14 to 2.90°C.  The greatest rise in monthly maximum temperature occurred in the January, March, May, July, August, September, and November. 

Days Greater Than 30°C

        In Canada, an extreme maximum daily temperature is defined as an event where the temperature is greater than (>) 30°C. Figure 11 shows the yearly number of extreme maximum daily temperature events that occurred in Kelowna from 1951 to 2025. These high temperature events average around 18 at the beginning of temperature record to around 34 by 2025, a 89% increase relative to the best-fit regression line.

Days Less Than 0°C

        Figure 12 shows the number of daily minimum temperature events less than (<) 0°C per year from 1951 to 2025. According to the best-fit regression line, the annual number of these events where the minimum daily temperature was below 0°C has dropped by 38 days (173 to 135) in 75 years.

Figure 12 Yearly number of minumum daily temperature events < 0°C from 1951 to 2025 in Kelowna. Minimum daily temperature events < 0°C have been steadily decreasing at a rate of about 5.0 days per decade according to linear regression analysis.

Figure 1 Location of the five weather stations used to reconstruct Kelowna’s climate record.

Figure 2 Kelowna’s annual average mean temperatures from 1951 to 2025. Annual average mean temperature has been steadily increasing at a rate of 0.27°C per decade according to linear regression analysis.

Figure 3 Kelowna’s annual average maximum and minimum temperatures from 1951 to 2025. Regression analysis suggests that annual average maximum temperature has been steadily increasing at a rate of 0.31°C per decade, while annual average minimum temperature has been steadily increasing at a rate of 0.22°C per decade.

Figure 8 Kelowna’s winter average mean temperatures from 1952 to 2025. Winter average mean temperature has been steadily increasing at a rate of 0.32°C per decade according to linear regression analysis.

Figure 5 Kelowna’s spring average mean temperatures from 1951 to 2025. Spring average mean temperature has been steadily increasing at a rate of 0.28°C per decade according to linear regression analysis.

Figure 7 Kelowna’s fall average mean temperatures from 1951 to 2025. Fall average mean temperature has been steadily increasing at a rate of 0.21°C per decade according to linear regression analysis.

Figure 10 The historical change in average monthly maximum temperatures for three periods: 1951 to 1980, 1981 to 2010, and 2011 to 2025.

Figure 11 Yearly number of maximum daily temperature events > 30°C from 1951 to 2025 in Kelowna. Maximum daily temperature events > 30°C have been steadily increasing at a rate of around 2.2 days per decade according to linear regression analysis.