Temperatures head higher in Agulhas Plain
Weather data from the Agulhas Plain shows that temperatures here have warmed significantly over the past 50 years. The mean maximum temperatures have risen on average 1.2 degrees Celsius since 1960. Minimum temperatures have risen 0.8 degrees Celsius over the same period. As a result, there has also been a small increase in the difference between maximum and minimum temperatures.
This is according to researcher Nicola van Wilgen and her co-researchers from SANParks and the South African Environmental Observation Network (SAEON). The researchers are assessing trends in the historical weather data from 64 SANParks national parks across the country, including the Cape Agulhas weather station. Across all the parks, the data shows that the most extreme high temperatures only occur after 1980.
The study has found that annual rainfall in the Southern Cape appears to be decreasing. For example, at one weather station in the Addo Elephant National Park, an average decrease of around two millimetres per year has been recorded over the past century. Van Wilgen says, “Though this might seem like a small amount every year, over time this adds up to hundreds of millimetres. Similar, though less dramatic decreases have also been recorded at other stations.”
However, trends in rainfall in the Agulhas region have been hard to determine. Van Wilgen says this is because the available data might be flawed. “Rainfall shows an exceptionally high peak throughout the 1950s. While there were some floods in the 1950s, researchers struggle to believe that the data is entirely accurate.”
She says the research team hopes to get further weather information from landowners on the Agulhas Plain. “We hope to get additional data to verify these and other patterns in the Agulhas region.” She has encouraged landowners on the Plain to contact her should they have good historical weather data, particularly for the period during the 1950s.
If you have such information, please contact Nicola: Nicola.VanWilgen@sanparks.org or Victoria: Victoria@saeon.ac.za.