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The mean temperature time-series over the period 1941–1996 for 13 stations across Sudan are examined on seasonal and annual bases to explore any possible trends in recent decades. Standardized anomaly indices (SAIs), intra-annual coefficients of variability, and autocorrelation coefficients are also developed. The consistency of both seasonal and annual patterns is also studied. South of latitude 16°N, the data show the tendency for annual time-series to follow mostly the wet-season time-series. The zone located northward is also an exception among other parts, as it does not reveal an actual change in its temperature series towards cooling or warming, but rather shows fluctuations between these two phases. In the rest of the country, a linear fit established for annual temperature series indicates significant upward trends, synchronized with those in wet- and hot-season series; the rising trends in the former seasonal series being higher and more significant. Since the 1940s, annual and wet-season temperatures have increased by 0·076–0·20 and 0·082–0·29°C per decade, respectively. The period of greater warmth in Sudan appears to coincide with that of rainfall depletion reported post mid-1960s. A general increase in the coefficient of variability (Cv) of the within-year monthly temperatures has also been noticed. This increase is statistically significant in northern and most central locations.

A comparative study of estimating the day-length, S0, and extraterrestrial radiation, H, is conducted, with special reference to Sudan. Due to the definitions of the formulae of Cooper and Hay, differences in S0-values are normal; however, the former formula revealed excellent agreement with data on the duration between sunrise and sunset. Hence, the paper recommends adopting Cooper's method for computing S0 for Sudan. With regard to H0, the use of the average days for the months, as recommended by Klein, has depicted no substantial errors. This has also been found true for day-length computations. The study further accentuates that the amount of solar energy available in Sudan is significantly large to be used for industrial purposes.

Several letters to the editor are presented in response to articles in previous issues including a bird sanctuary on Wallasea Island in the Thames River Estuary in the September 13, 2012 issue, a third runway in Heathrow, England in the September 13, 2012 issue and airport expansion in Great Britain in the September 13, 2012 issue.

Several letters to the editor are presented in response to articles published in previous issues of the journal including one commenting on "Atkins Issues Warning to Ofwat Over Water Future," published on October 22, 2009 issue; another on the British Construction Industry Awards supplement, and yet another on sustainability of high speed trains.

Several letters to the editor are presented in response to articles in previous issues including "Highways Agency to drop ECI," published in the April 9, 2009 issue, another related to coastal defence resource, and yet another related to sustainability.

Several letters to the editor are presented in response to articles in previous issues including one on worker exploitation in the United Arab Emirates in the January 18, 2007 issue, "New Buildings Need to Reflect Climate Change," and the article on Thomas Telford in the January 11, 2007 issue.