Climate Hazards

Projected average annual maximum temperature relative to the 1961-1990:

• There is high confidence in the climate change signal when looking at maximum temperatures over the Free State region.
• Most Free State districts are projected to experience significant increases in annual maximum temperatures towards the end of the century in a 3-degree world.
• The changes over the escarpment within the Thabo Mofutsanyane and Xhariep regions are slightly low (i.e., close to the global warming levels) but still pronounced considering that we are using 1961-1990.

Reference period (1961-1990) average annual minimum temperatures:

Projected average annual minimum temperature relative to the 1961-1990:

• There is high confidence in the climate change signal when looking at minimum temperatures over the Free State region.
• By the end of the century (in a 3-degree world), the lowveld regions within Lejweleputswa, Fezile Dabi, and Xhariep are expected to experience significantly higher annual minimum temperatures.
• The minimum temperature changes over the escarpment are relatively low (i.e., close to the global warming levels).

Reference period (1961-1990) average annual mean temperatures:

Projected  average annual mean temperature relative to the 1961-1990:

• There is high confidence in the climate change signal looking at mean temperatures over the Free State region.
• By the end of the century, most districts in Free State are projected to experience significantly higher annual mean temperatures in a 3-degree world.
• The changes over the escarpment, within the Thabo Mofutsanyana and Xhariep regions, are relatively low (i.e., close to the global warming levels).

Reference period (1961-1990) average annual universal thermal climate index:

Projected average annual universal thermal climate index relative to the 1961-1990:

• There is high confidence in the climate change signal looking at the universal thermal climate index over the Free State region.
• Most Free State districts are projected to experience significant increases in the universal thermal climate index towards the end of the century in a 3-degree world.
• The changes over the escarpment, within the Thabo Mofutsanyana region, are relatively low (i.e., close to the global warming levels).

Source: CSIR

This series of maps illustrate two climate extreme indices, depicting projected changes in 1) annual total number of very heavy rainy days ≥ 20mm and 2) annual maximum 5-day rainfall days. For each metric, the projected changes in average global temperatures are shown for warming levels of 1.5°C, 2.0°C, and 3.0°C, relative to the baseline period of 1961–1990. The above climate extreme indices indicate that a large part of the Free State may experience an increased number of days of rainy days while some parts will experience no change or decreased number of days of rainy days.

This will have implications for Agriculture, Water Resources, and Food Security, Disaster Risk Reduction, and Forestry/GHGs due to heavy rainfall events. The heavy rainfall events resulting from these number of extreme rainy days can impact various sectors in different ways.

Reference period (1961-1990) average annual total number of very heavy rainy days ≥ 20mm:

Projected annual total number of very heavy rainy days
relative to the 1961-1990:

• There is no confidence in the direction of the average annual total number of very heavy rainy days change over Free State.
• The uncertainty is pronounced as the global temperature reaches 2.0 degrees.
• The 10th percentile of the Model distribution is suggestive of a decrease, while the Median (50th percentile) and 90th percentile indicate a slight increase and a significant increase in very heavy rainy days, respectively.
• The conclusion is that a larger part of the Free State is projected to experience increased chances of the total number of very heavy rainy days.

Reference period (1961-1990) average annual maximum 5-day rainfall total:

Projected annual maximum 5-day rainfall total relative to the 1961-1990:

• There is no confidence in the direction of the average annual maximum 5-day rainfall total change over Free State.
• The 10th percentile of the model distribution suggests a decrease in the maximum 5-day rainfall total.
• The Median (50th percentile) and 90th percentile suggest no change and a slight increase in the maximum 5-day rainfall total.
• The conclusion is that a larger part of the Free State is projected to experience a no change or slight increase in maximum 5-day rainfall total as the global temperature reaches 2.0 and 3.0 degrees Celsius.

Source: CSIR

This series of maps illustrate two climate extreme indices, depicting projected changes in 1) annual maximum number of consecutive dry days and 2) annual standardized precipitation index (SPI). For each metric, the projected changes in average global temperatures are shown for warming levels of 1.5°C, 2.0°C, and 3.0°C, relative to the baseline period of 1961–1990. The above climate extreme indices indicate that a large part of the Free State may experience a drier future like much of the Southern Hemisphere is expected to experience an increased likelihood of drought, as well as a higher chance of low-frequency, high-impact rainfall extremes.

This will have implications for Health, Agriculture, Water Resources, and Food Security, Disaster Risk Reduction, and Forestry/GHGs due to dry conditions for longer periods. The dry conditions resulting from these number of consecutive dry days and SPI can impact various sectors in different ways.

Reference period (1961-1990) average annual maximum number of consecutive dry days:

Projected annual maximum number of consecutive dry days relative to the 1961-1990:

• There is low confidence in the direction of the average annual maximum number of consecutive dry days change over Free State.
• Most Free State districts are projected to experience significant increases in the maximum number of consecutive dry days towards the end of the century in a 3-degree world.
• The 10th percentile suggests no change and a slight increase, while the Median (50th percentile) and 90th percentile indicate a significant increase in the maximum number of consecutive dry days.
• The Free State is projected to experience an increase in the maximum number of consecutive dry days/droughts.

Reference period (1961-1990) standardized precipitation index (SPI) trends:

Projected standardized precipitation index (SPI) trends:

• There is no confidence in the direction of the average annual standardized precipitation index change over Free State.
• The 10th percentile aligns with the IPCC 6th assessment report, indicating a drier future for Southern Africa. The Median (50th percentile) and 90th percentile projects show uncertainties with some showing an increase and some showing a decrease in SPI.
• The Free State is projected to experience an increase (negative values) in the standardized precipitation index with a significant test (dotted).
• The Free State, like much of the Southern Hemisphere, is expected to experience an increased likelihood of drought, as well as a higher chance of low-frequency, high-impact rainfall extremes.

Source: CSIR

This series of maps illustrate two climate extreme indices, depicting projected changes in 1) annual heatwave duration and 2) annual heatwave magnitude. For each metric, the projected changes in average global temperatures are shown for warming levels of 1.5°C, 2.0°C, and 3.0°C, relative to the baseline period of 1961–1990. The above climate extreme indices indicate that a large part of the Free State may experience an increased length of the longest heatwaves, however, the magnitude of the heatwaves might not intensify/experience no change in the near future but increase in the far future.

This will have implications for Health, Agriculture, Water Resources, and Food Security, Forestry/GHGs, and Energy due to heat stress. The heat stress resulting from the length of the longest heatwave and its magnitude can impact various sectors in different ways.

Reference period (1961-1990) average annual heatwave duration:

Projected average annual heatwave duration relative to the 1961-1990:

• There is high confidence in the climate change signal looking at heatwave duration over the Free State region.
• Most Free State districts are projected to experience a significant increase in annual heatwave duration towards the end of the century in a 3-degree world.
• The heatwave duration changes over the escarpment are relatively low (i.e., close to the global warming levels).

Reference period (1961-1990) average annual heatwave magnitude:

Projected average annual heatwave magnitude relative to the 1961-1990:

• There is low confidence in the climate change signal looking at heatwave magnitude over the Free State region.
• Heatwave magnitudes over Free State are projected to remain the same for all the percentiles and GWLs. However, we see a likelihood of a significant increase as the global temperature reaches 3.0 degrees.
• The changes in the heatwave magnitudes remain the same until close to the global warming levels.

Source: CSIR

This series of maps illustrate one climate extreme index, depicting projected changes in 1) Fire weather index ≥ 24. For this metric, the projected changes in average global temperatures are shown for warming levels of 1.5°C, 2.0°C, and 3.0°C, relative to the baseline period of 1961–1990. The above climate extreme index indicates that a large part of the Free State may experience an increased number of days with a fire weather index ≥ 24 indicating the likelihood of change of wildfire.

This will have implications for Health, Agriculture, Water Resources, and Food Security, Disaster Risk Reduction, Energy, and Forestry/GHGs due to the number of days with a fire weather index ≥ 24. The fire weather index resulting from the number of days with a fire weather index ≥ 24 can impact various sectors in different ways.

Reference period (1961-1990) average annual fire weather index ≥ 24:

Projected average annual fire weather index ≥ 24 relative to the 1961-1990:

• There is low confidence in the climate change signal looking at the fire weather index over the Free State region.
• The 10th percentile suggests a decrease and a slight increase in the fire weather index over the Lowveld of Free State.
• The Median (50th percentile) and 90th percentile suggest a significant increase in the fire weather index.
• The changes over the escarpment, within the Thabo Mofutsanyana region, are relatively low (i.e., close to the global warming levels).

Source: CSIR

This series of maps illustrates one climate extreme index, depicting projected changes in Frost Days. Frost Days (FD) is defined as the sum of the days where the minimum air temperature is equal to or below 0 °C during the period of interest (yearly and seasonally).

For this metric, the projected changes in the sum of days where the minimum air temperature is equal to or below 0 0C are calculated for global warming levels of 1.5°C, 2.0°C, and 3.0°C, relative to the baseline period of 1961–1990. The climate extreme index indicates that a large part of the Free State may experience a decline in the number of frost days. This will have positive and negative impacts mainly on the Agricultural Sector as frost-free days will allow for longer growing seasons, ultimately increasing crop production and outputs. On the other hand, longer growing seasons will require water for irrigation.

Reference period (1961-1990) Frost Days (FD):

Projected Frost Days (FD) relative to the 1961-1990:

• Frost Days (FD)- Sum of the days where the minimum air temperature is equal to or below 0 °C annually.

• There is high confidence in the climate change signal looking at the frost days over the Free State region.

• The Free State generally experiences frost days that endanger the agricultural sector the most.

• The number of frost days over the Free State are projected to have a significant reduction. The reduced number of frost days are likely to increase with increasing GWLs.

• The most changes will be experienced over the escarpment regions, especially along the eastern tip of the Thabo Mofutsanyana region.

Reference period (1961-1990) Frost Days (FD):

Projected Frost Days (FD) relative to the 1961-1990:

• Frost Days (FD)- Sum of the days where the minimum air temperature is equal to or below 0 °C during the June-July-August winter season.
• There is high confidence in the climate change signal looking at the frost days over the Free State region.
• The number of frost days over the Free State are projected to have a significant reduction. The reduced number of frost days are likely to increase with increasing GWLs.
• The most changes will be experienced over the escarpment regions, especially along the south-east of Fezile Dabi, most of Thabo Mofutsanyana and the Mangaung Districts, as well as the east-southern Lejweleputswa District.