|Updated : 21/9/2014|
Climate - Benoni
Source : SaExplorer
Temperature scale of hardiness zones, showing the average annual minimum temperature in degrees Celsius. The main factors determining average minimum temperature are elevation, latitude and proximity to the coast.
A hardiness zone (a subcategory of Vertical Zonation) is a geographically defined area in which a specific category of plant life is capable of growing, as defined by climatic conditions, including its ability to withstand the minimum temperatures of the zone (see the scale on the left). For example, a plant that is described as "hardy to zone 10" means that the plant can withstand a minimum temperature of -1°C. A more resilient plant that is "hardy to zone 9" can tolerate a minimum temperature of -7°C.
Based on the scale and the average temperatures shown above Benoni has a hardiness rating of H10 and is therefore suitable for the growing of plant of hardiness rating H1 to H10.
Distribution of Average First Date of Heavy FrostSource : http://planet.botany.uwc.ac.za/nisl/Invasives/Assignments/GARP/atlas/atlas_toc.htm
On average first frost occurs in May over most of the interior of South Africa. However, the high lying Drakensberg and Maluti mountains already experience their first heavy frosts as early as February/March. Relevant statistics on first heavy frost occurrences appear in the table below. If the Free State is taken by way of example, results imply that on average by 11 May, 20% of the Free State has experienced a severe frost, by 16 May 50% has had its first severe frost and by 22 May, 80% of the Free State has had its first severe frost. Computations by this equation were terminated on July 3 (hence the "Early July" designation) after which a "Last Severe Frost Date" equation came in operation.
Distribution of Average Last Date of Heavy FrostSource : http://planet.botany.uwc.ac.za/nisl/Invasives/Assignments/GARP/atlas/atlas_toc.htm
Patterns of average last date of heavy frost are, effectively, a reversal of those of the first heavy frost date. Most of the interior experiences last frosts towards the end of August and early September, but in the high Drakensberg frosts are predicted to persist into early December. The statistics show that Swaziland is effectively frost free by mid-July, the Northern Province by the end of July, while 80% of the Free State and Eastern Cape have heavy frosts persisting into the second half of September.
*Unreliable : Extrapolated beyond last observed date of 22 November
Using the Gauteng extremes of the above tables for first and last frost dates then Benoni will have between 261 and 291 frost free growing days with a mean of 272 days.