COLUMBIA, S.C. — When it comes to temperatures, things are normally pretty simple. We see our coldest weather of the day in the morning and our warmest weather in the afternoon.
There’s actually an official weather term for this, Diurnal Heating, or the temperature range over a span of 24 hours. This normally includes a low temperature in the morning and a high temperature in the afternoon.
This value between the two can change. Late fall sees the biggest spread between these two values thanks to cold mornings and sometimes warm afternoons. The average change in temperatures is around 28 degrees this time of the year but can vary greatly.
In 1990 Halloween featured a massive swing of 45° during the day. This is in stark contrast to just a year ago when the day only saw a 3-degree difference.
Tuesday will fall somewhere in the middle with around a 20-degree swing in temperatures but it might not occur as you think.
Southerly winds ahead of a cold front will allow for a mild Monday to lead into temperatures around the upper 60s at midnight. This will likely be as warm as we get as cold air moves into the region setting our low temperature for the day all the way at 11:59 PM before we get to Wednesday.
These “backward” temperatures occur very often when fronts move through the Midlands and Tuesday will be a prime example of this.
Because of this, Halloween will likely end up as the coldest in 3 years with our first hard freeze on the way in the days to come.