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Heat in Ward 18, Nelson Mandela Bay

Summer 2025/26: the ground in Ward 18, Nelson Mandela Bay reached about 42 °C on clear mornings. That is the ground (roofs, roads, soil), not the air. The third hottest summer since 2014. In summer the ground here reads +3.8 °C against its municipality’s average (since 2014).

Land surface temperature is how hot the ground itself is: roofs, roads, bare soil and leaves, as a satellite sees them from above. Landsat passes at about 10 in the morning and sees only through clear skies. It is not the air temperature a weather station gives: on a sunny day the ground is often 10 to 20 degrees hotter than the air, and hard, dark, dry surfaces heat up most while trees, grass and water stay cooler.

What it is not: not the afternoon peak, not the night, not the air you feel in the shade, and not a reading at any one house. A month with clouds rests on few clear looks.

Summer 2025/26

Every summer since 1987

Summer 1986 to 87: 39.8 °CSummer 1990 to 91: 38.8 °CSummer 1991 to 92: 39.0 °CSummer 1992 to 93: 38.1 °CSummer 1993 to 94: 40.3 °CSummer 1994 to 95: 33.0 °CSummer 1996 to 97: 35.9 °CSummer 1998 to 99: 37.0 °CSummer 1999 to 00: 41.3 °CSummer 2000 to 01: 39.1 °CSummer 2001 to 02: 38.4 °CSummer 2002 to 03: 40.5 °CSummer 2006 to 07: 37.9 °CSummer 2011 to 12: 42.2 °CSummer 2012 to 13: 41.7 °CSummer 2013 to 14: 42.4 °CSummer 2014 to 15: 39.9 °CSummer 2015 to 16: 41.9 °CSummer 2016 to 17: 42.9 °CSummer 2017 to 18: 41.6 °CSummer 2018 to 19: 41.5 °CSummer 2019 to 20: 38.6 °CSummer 2020 to 21: 39.8 °CSummer 2021 to 22: 39.3 °CSummer 2022 to 23: 38.2 °CSummer 2023 to 24: 38.2 °CSummer 2024 to 25: 38.9 °CSummer 2025 to 26: 42.2 °C199019952000200520102015202020252026
Each summer (December to February, named by the year it ends) on clear mornings. Bars start at 31 °C, not zero. Darker: Landsat 8 and 9 (from 2014); lighter: Landsat 5 and 7. A gap is a summer seen too little.
Show the numbers
Land surface temperature each summer, 1987 to 2026: every figure
When or whatFigure
Summer 1986 to 8739.8 °C
Summer 1990 to 9138.8 °C
Summer 1991 to 9239.0 °C
Summer 1992 to 9338.1 °C
Summer 1993 to 9440.3 °C
Summer 1994 to 9533.0 °C
Summer 1996 to 9735.9 °C
Summer 1998 to 9937.0 °C
Summer 1999 to 0041.3 °C
Summer 2000 to 0139.1 °C
Summer 2001 to 0238.4 °C
Summer 2002 to 0340.5 °C
Summer 2006 to 0737.9 °C
Summer 2011 to 1242.2 °C
Summer 2012 to 1341.7 °C
Summer 2013 to 1442.4 °C
Summer 2014 to 1539.9 °C
Summer 2015 to 1641.9 °C
Summer 2016 to 1742.9 °C
Summer 2017 to 1841.6 °C
Summer 2018 to 1941.5 °C
Summer 2019 to 2038.6 °C
Summer 2020 to 2139.8 °C
Summer 2021 to 2239.3 °C
Summer 2022 to 2338.2 °C
Summer 2023 to 2438.2 °C
Summer 2024 to 2538.9 °C
Summer 2025 to 2642.2 °C

The shape of a year

January: 40.3 °CFebruary: 39.5 °CMarch: 34.6 °CApril: 28.7 °CMay: 22.5 °CJune: 19.0 °CJuly: 17.6 °CAugust: 22.6 °CSeptember: 28.0 °COctober: 33.3 °CNovember: 37.0 °CDecember: 41.1 °CJanFebMarAprMayJunJulAugSepOctNovDec
Each month’s average since 2014, clear mornings. Bars start at 15 °C.
Show the numbers
Land surface temperature by calendar month, since 2014: every figure
When or whatFigure
January40.3 °C
February39.5 °C
March34.6 °C
April28.7 °C
May22.5 °C
June19.0 °C
July17.6 °C
August22.6 °C
September28.0 °C
October33.3 °C
November37.0 °C
December41.1 °C

Month by month

MonthLand surface temperatureClear looks
October 202631.2 °C5.9
September 202628.5 °C2.7
August 202619.5 °C4.0
July 202617.6 °C4.3
June 202620.8 °C4.4
May 202621.7 °C5.0
April 202626.5 °C5.8
March 202634.6 °C4.5
February 202640.3 °C4.0
January 202643.4 °C4.9
December 202542.8 °C6.2
November 202539.8 °C3.9
October 202533.4 °C4.1
September 202530.3 °C5.5
August 202523.9 °C3.1
July 202517.1 °C3.2
June 202518.9 °C4.5
May 202522.6 °C6.2
April 202529.5 °C4.0
March 202534.5 °C3.3
February 202538.1 °C1.6
January 202539.5 °C1.2
December 202439.1 °C2.9
November 202436.8 °C2.8

“Clear looks” is how many times the average 240 m patch of the place was seen through clear sky that month. Under one, part of the place was not seen at all, so the figure leans on the part that was.

Nelson Mandela Bay and its wards · Every municipality, ranked

Source

Measured from space by the American Landsat satellites: the ground, not the air.

How we worked this out

Landsat 5 to 2011, Landsat 7 to bridge the gaps, Landsat 8 and 9 from 2013: different satellites pass at slightly different times, so compare summers within the same years first.

What we changed: we kept only the clear land cells (no cloud, cloud shadow, snow or water, with a margin round each cloud), read them at 480 m, and averaged them over each 2026 ward each month; larger places are the sums of their wards.

Landsat imagery courtesy of the U.S. Geological Survey (Landsat Collection 2 surface temperature, through Digital Earth Africa’s copy).

Dataset: land surface temperature by ward, release of 13 November 2026.

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