Technical note on addition of data for Kelburn, December 1927

Temperature data for December 1927 at Kelburn have been added to the NIWA Climate Database

Temperature data for December 1927 at Kelburn (agent number 3385) have been added to the NIWA Climate Database. Kelburn is one of the sites used to create the 'Wellington' record for the NIWA seven-station temperature series.

The New Zealand Meteorological Service moved their climate observation site from Thorndon (agent number 3391) to Kelburn at the beginning of 1928. There was a very short period of overlap, just 29 days covering 3–31 December 1927, when daily weather observations were made at both sites. The paper records of the 1927 measurements at Kelburn were not digitised when computer records were originally set up. These Kelburn data for the overlap month with Thorndon have now been added to NIWA’s publicly available Climate Database.

Such a short period is not acceptable for determining the climatological differences between sites. However, we note that in the “Monthly_Stats” table on the database, the average daily mean temperature for December 1927 shows 14.7ºC at Thorndon (31 days) and 13.7ºC at Kelburn (29 days only), so Kelburn was 1.0ºC colder than Thorndon that month. If the first 2 days of December are removed from the Thorndon average (so exactly the same 29-day period is compared), then the Thorndon average increases to 14.9ºC and the Kelburn-Thorndon site difference to 1.2ºC. This 29-day offset of 1.2ºC is more extreme than the climatological offset of 0.8ºC specified in the “seven-station” Schedule of Adjustments. The original measurements were, of course, made in degrees Fahrenheit, but have been converted to degrees Celsius on the database. Scanned copies of the original December 1927 observations for Thorndon and Kelburn are below. Click on the image to expand.