Yes, it’s true… scientists have evidence supporting the widespread perception that trees make rain, that growing more vegetation, we get more rain.[1]

On average, 40% or more of the precipitation over land originates from evaporation and the transpiration of water from plants.[2] Forests like the Amazon don’t merely grow in wet areas; they create and maintain the conditions in which they grow by increasing rainfall and reducing the length of the dry season.[3]

When vegetation gets cleared, wet seasons come later, and less water is available in the landscape for evaporation and transpiration, suppressing precipitation. [3][4]

For example, more rain used to fall on the western side of a 750 km long fence built to exclude rabbits in southwest Australia. Today, however, the land on the eastern side of the barrier gets higher rainfall. This is because, on the western side, most of the vegetation has since been removed for arable cropping.[5]

Aerial photo of rabbit proof fence and trees making rainCloud cover either side of the Rabbit-Proof Fence (©Earth Observing Laboratory)

Growing more vegetation over large areas, we also increase the transportation of moisture inland – the Biotic Pump Theory.

Research demonstrates that for more than 60% of the tropical land surface, the air that has passed over extensive vegetation in the preceding few days produces at least twice as much rain as air that has passed over little vegetation. [6]

Large-scale deforestation reduces rainfall in some areas by up to 30%, and reliable rainfall in continental interiors of Africa, Australia and elsewhere, appears to depend on maintaining relatively intact and continuous forest cover from the coast.[7]

Transforming landscapes from forests to fields has at least as big an impact on regional climates as climate change.[8]

Image showing how trees make rain

The effects of Deforestation on Rainfall[9]

How to make Rain Happen!

It’s great to know that trees make rain, but trees are being cleared at a faster rate than any time in history! How can we possibly reverse this? How can we get it to rain more in our regions?

Image showing women planting trees

  1. Share the science – see references below
  2. Change the story we tell about the value of trees and everyone in your community will be out planting trees!
  3. Learn how to make the most of your rain using eco-logical techniques with these publications from Learning from NatureFront cover - How to Drought-Proof Your Farm Front cover drought-proof your garden

References for Trees make Rain

[1] Shukla, J and Mintz, Y, 1982. Influence of Land-Surface Evapotranspiration on the Earth’s Climate Science19 Mar 1982: 1498-1501. Vol. 215, Issue 4539, pp. 1498-1501
DOI: 10.1126/science.215.4539.1498 (

[2] Trees, forests and water: Cool insights for a hot world. David Ellison, Cindy E. Morris, et al. 2017. Global Environmental Change 43 (2017) 51–61 (

[3] Jonathon S. Wright, Rong Fu, John R. Worden, Sudip Chakraborty, Nicholas E. Clinton, Camille Risi, Ying Sun, Lei Yin, 2017, Rainforest-initiated wet season onset. Proceedings of the National Academy of Sciences Aug 2017, 114 (32) 8481-8486; DOI: 10.1073/pnas.1621516114 (

[4] Spracklen, D., Arnold, S. & Taylor, C. 2012, Observations of increased tropical rainfall preceded by air passage over forests. Nature 489, 282–285 doi:10.1038/nature11390 (

[5] Nair et al-2011-Journal of Geophysical Research-Atmospheres (1984-2012) The role of land-use change on the development and evolution of the west coast trough, convective clouds, and precipitation in southwest Australia (

[6] Spracklen, D., Arnold, S. & Taylor, C. 2012, Observations of increased tropical rainfall preceded by air passage over forests. Nature 489, 282–285 doi:10.1038/nature11390 (

[7] Charles Massey – Farming in the Middle East and Australia: lessons about a brittle climate. ABC Saturday Extra (

[8] Judith D. Schwartz, 2013, Clearing Forests May Transform Local—and Global—Climate, Scientific American March 4, 2013 (

[9] Aragão, L. The rainforest’s water pump. Nature 489, 217–218 (2012) (


    2 replies to "Trees make Rain – there is science now to prove it!"

    • Suzanne

      How many trees make rain? I’ve planted thousands & different types. Nothing
      No change with the rain. 23 ac 400 fruit trees all types, 16 Varieties of eucalyptus deciduous trees, flowering trees,

      • admin

        Hi Suzanne Me too! But we need to get our neighbours doing it too – as mentioned in the article we are talking about change at the landscape scale…

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