I'm currently reading 'The diamond diggings of South Africa' by Charles Payton, a first-hand account of a visit to the diamond mines in 1871.
On page 80 it says
For the first fortnight from leaving Algoa Bay we use to "trek" chiefly by night, seldom traveling after 8 a.m. till about 4 p.m., then perhaps moving on till 9, "tying up" oxen till 12 or 1 a.m., and then going on again till daylight.
And on page 83
When at length, on the evening of the 30th May, after a rather rough crossing of the Modder River in the dark...
It seems to me that it's one thing to travel at night in a modern vehicle with headlights on modern roads which often have streetlights and enough general illumination from nearby cities to see where you're going. But in the frontier era, with no headlights, no city lights to speak of, it would be pitch dark at night; how was travel at night possible? How would you manage to stay on the road, even?
And why? I could understand if the daytime temperature were unbearably hot, but late May in the southern hemisphere is early winter, and the rest of the text confirms that the temperature in that time and place was if anything uncomfortably chilly. What benefit was gained from traveling at night?