Adventures in Teaching and Learning

What is Humidity?
Humidity is the amount of moisture in the air. It can be measured in various ways, but the most usual is to describe it as ‘relative’ humidity. This is expressed as a percentage. A relative humidity of 100% means the moisture content of the air is the maximum possible at any particular temperature. The hotter the air, the more moisture it can hold.

Why is it Important?
When relative humidity is low, evaporation is rapid. Soil dries out, wet clothes dry quickly and perspiration evaporates from the skin. When relative humidity is high, clothes dry slowly and body sweat cannot evaporate easily. We feel sticky and hot and because our perspiration cannot evaporate quickly, we feel uncomfortable. We can stand dry heat much better than damp heat which makes us feel listless and takes our energy away.

Taken from the BBC Weather Centre.

I mention this because it’s so, so hot here at the moment, in sticky London, that I can hardly move or get on with anything. But when I was in Malawi, it was even hotter, and I don’t remember it being as difficult to get on with everything as it is here. So, I looked at the BBC’s 24 hour forecast, and discovered that at present it’s somewhere between 76% and 83% humidity – and should head up to about 93% at 7am tomorrow morning. With thunder expected around 1am. Hopefully will get better after that!

NOTE: I have just been enticed away from my computer by the gentle sound of falling rain! It’s 12:25am … hopefully this might clear the air for a bit – and it’s interesting to see that the forecast was quite accurate!

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