A Warm March?

By Paul Homewood

 

 

 

Last month was the 13th warmest March in England, according to average maximum temperatures, though much cooler than March 1938.

This may come as a shock to many, who only remember long spells of cold winds and rain. (On a personal note, March often sees my first serious bike ride of the year, and I can vouch for many pleasantly warm days in years past; nothing this year has compared to that).

I have carried out an analysis of daily CET maximums for each March going back to 1878, and it sheds a lot of light on what has been going on this year, and indeed in recent years.

The first chart plots the highest temperature recorded each year in March. The highest last month was a pretty dismal 15.2C. The record stands at 22.2C in 1965, and the average for the series of 15.0C.

What is also significant though is that this upper banding shows no evidence of increasing – certainly not in comparison with the 1950s and 60s.

If there really was a climatic shift taking place, you would expect to see both upper and lower bands rising. (Think of a comparison of, say, London and Leeds – London temperature bands would be consistently higher than in the colder Leeds.)

Now let’s look at the coldest temperatures recorded each year. In March 2024 this dropped to 5.7C, much higher than the series average of 4.2C. Moreover, generally speaking, the lowest temperatures have been steadily increasing in the last couple of decades. Since 2010, for instance, eight years have had lowest temperatures above 6.0C. In contrast, between 1951 and 1970 this only occurred in four years.

We can put both bands together:

 

The conclusion is clear; the rise in average temperatures in recent years has more to do with less extreme cold weather than with more extreme hot weather.

Indeed this is immediately apparent from this year’s CET graph. For pretty much the whole month of March, temperatures never reached unusually high levels, but also never dipped into below average territory:

In other words, what have been seeing is WEATHER not CLIMATE. This is an important distinction because it suggests that temperatures are not marching upwards in lockstep with CO2 levels. As such there would appear to be a limit as to how much further average temperatures can rise.

While that may remain speculation, we can certainly say that the UK climate has been getting milder in recent years, not more extreme as often claimed.