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Heat in Sundays River Valley

Summer 2025/26: the ground in Sundays River Valley reached about 37 °C on clear mornings. That is the ground (roofs, roads, soil), not the air. The 5th hottest of 13 summers 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: 35.2 °CSummer 1990 to 91: 34.5 °CSummer 1991 to 92: 33.9 °CSummer 1992 to 93: 35.8 °CSummer 1993 to 94: 32.9 °CSummer 1995 to 96: 28.7 °CSummer 1996 to 97: 30.5 °CSummer 1998 to 99: 34.1 °CSummer 2000 to 01: 33.7 °CSummer 2001 to 02: 33.6 °CSummer 2002 to 03: 31.5 °CSummer 2011 to 12: 33.8 °CSummer 2012 to 13: 33.6 °CSummer 2013 to 14: 37.5 °CSummer 2014 to 15: 36.4 °CSummer 2015 to 16: 37.8 °CSummer 2016 to 17: 39.5 °CSummer 2017 to 18: 37.2 °CSummer 2018 to 19: 37.9 °CSummer 2019 to 20: 35.7 °CSummer 2020 to 21: 37.0 °CSummer 2021 to 22: 36.2 °CSummer 2022 to 23: 36.7 °CSummer 2023 to 24: 35.6 °CSummer 2024 to 25: 35.1 °CSummer 2025 to 26: 37.4 °C199019952000200520102015202020252026
Each summer (December to February, named by the year it ends) on clear mornings. Bars start at 26 °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 8735.2 °C
Summer 1990 to 9134.5 °C
Summer 1991 to 9233.9 °C
Summer 1992 to 9335.8 °C
Summer 1993 to 9432.9 °C
Summer 1995 to 9628.7 °C
Summer 1996 to 9730.5 °C
Summer 1998 to 9934.1 °C
Summer 2000 to 0133.7 °C
Summer 2001 to 0233.6 °C
Summer 2002 to 0331.5 °C
Summer 2011 to 1233.8 °C
Summer 2012 to 1333.6 °C
Summer 2013 to 1437.5 °C
Summer 2014 to 1536.4 °C
Summer 2015 to 1637.8 °C
Summer 2016 to 1739.5 °C
Summer 2017 to 1837.2 °C
Summer 2018 to 1937.9 °C
Summer 2019 to 2035.7 °C
Summer 2020 to 2137.0 °C
Summer 2021 to 2236.2 °C
Summer 2022 to 2336.7 °C
Summer 2023 to 2435.6 °C
Summer 2024 to 2535.1 °C
Summer 2025 to 2637.4 °C

The shape of a year

January: 37.4 °CFebruary: 34.8 °CMarch: 30.2 °CApril: 25.5 °CMay: 20.2 °CJune: 17.1 °CJuly: 16.2 °CAugust: 20.2 °CSeptember: 25.2 °COctober: 31.3 °CNovember: 34.8 °CDecember: 38.6 °CJanFebMarAprMayJunJulAugSepOctNovDec
Each month’s average since 2014, clear mornings. Bars start at 14 °C.
Show the numbers
Land surface temperature by calendar month, since 2014: every figure
When or whatFigure
January37.4 °C
February34.8 °C
March30.2 °C
April25.5 °C
May20.2 °C
June17.1 °C
July16.2 °C
August20.2 °C
September25.2 °C
October31.3 °C
November34.8 °C
December38.6 °C

Warmest and coolest wards

Each ward’s summers against Sundays River Valley’s average, since 2014. Where the ground is mostly roofs, roads and bare earth it reads hotter; where there are trees, grass, gardens or water it reads cooler.

Every ward

Places in each ward: © OpenStreetMap contributors.

Month by month

MonthLand surface temperatureClear looks
October 202626.3 °C3.1
September 202623.5 °C1.4
August 202617.8 °C2.5
July 202614.6 °C2.2
June 202617.5 °C2.1
May 202618.3 °C2.9
April 202623.3 °C2.8
March 202631.1 °C2.5
February 202633.9 °C3.0
January 202638.9 °C2.4
December 202539.3 °C2.9
November 202538.2 °C2.1
October 202529.9 °C3.0
September 202525.9 °C3.5
August 202518.6 °C2.4
July 202517.2 °C1.9
June 202517.3 °C3.0
May 202521.2 °C4.1
April 202525.8 °C3.5
March 202530.1 °C2.2
February 202533.4 °C1.4
January 202535.8 °C1.0
December 202436.2 °C1.9
November 202433.7 °C1.9

“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.

Every municipality, ranked · Everything we hold for Sundays River Valley

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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