At what temperature does rain become not chilling?

Question

I live at 53 degrees latitude, where the effect of being caught out in the rain and getting wet is always to become uncomfortably cold.

However, I would expect this to depend on the ambient temperature. Looking at videos of heavy showers of rain in the tropics, my intuition says being caught out in them would result in severe chill, but that intuition was trained at high latitude, and might not be at all accurate in the tropics.

How high does the ambient temperature need to get before being caught out in the rain (wearing just a T-shirt, not a waterproof jacket or suchlike) stops being hazardous or unpleasant, and becomes neutral or welcome? Is such a temperature often encountered in the tropics?

Answer 1

I'd say, very hard to answer as it depends on a lot of factors, especially personal preference (e.g. I get cold if I'm tired or hungry). Other factors would include exposure time, wind, sunny/cloudy, activity, previous acclimatization. I think a combination of these would result in a range of somewhere around 10°C where it doesn't feel unpleasant.

Anecdotal evidence: Lived in India for some time. For me it was somewhere around the 24°C where it wasn't unpleasant anymore. But if it is overcast, humid (i.e. clothes don't dry fast) and you are cycling somewhere (windchill) and it rains continuously, it can get cold quite fast. If you are used to 30°C weather, it feels quite cold when it drops down to 22°C. On the other hand during summer monsoon, you might get a 10 minute downpour, clouds move on, sun comes out and it's back to 30°C. This can be quite nice because you dry of very quickly (at which point you have to deal with extremely high humidity).

Is such a temperature often encountered in the tropics?

If we consider 30°C the point where rain definitely isn't uncomfortably cold, yes, that happens quite often. If, for example we look at the climate diagram for Chennai, India, where the main rainy season is on October and November, which coincides with an average high of 30+°C. Of course, rain usually means a slight drop in temperature, but you get the picture.

Answer 2

I live quite a bit further north than that, and my main complaint about getting caught in the rain is to get wet. Scotland is notorious for having some very wet days.

But rain rarely gets cold here as the air temperatures tend to vary between around 0C in winter to 20C in summer (can be colder in the mountains etc). The coldest precipitation is when we get sleet - that lovely combination of snow and rain that can happen just around 0C. Combined with a high wind this can cause significant wind chill.

So I'm assuming if you get cold rain at lower latitudes you must be further from the coast, so your cooling is going to be unrelated to latitude, or at least less impacted by latitude.