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Understanding the Weather

What is relative humidity?

Relative humidity is the ratio of the amount of water vapour in the air to the amount it could hold if it was saturated. As temperature increases, the amount of water vapour the air can hold increases. Therefore, relative humidity decreases with increasing temperature assuming the amount of water vapour in the air stays the same. As a result, relative humidity goes through a diurnal cycle inverse to temperature, peaking in the early morning and reaching a minimum during the afternoon. For this reason, it is not the best guide to the amount of water vapour in the air - that would be the dew point.

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Cotton growers planting only 20 per cent of last year's crop as drought hits hard

ABC image 17:48 EST Queensland cotton growers are planting only 20 per cent of the crop they planted last year as the drought continues to take its toll.

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