A simple method for estimating daily and monthly mean temperatures from daily minima and maxima

Abstract

Historical near-surface air temperature data from many locations are available as time series of daily minimum and maximum temperatures. However, estimation of the daily and monthly mean temperatures as the average of the minimum and the maximum is prone to large errors. Therefore, a simple method for estimating the mean daily temperature on the basis of minima and maxima is presented. The proposed method accounts for the temperature trend by including the minimum temperature on the following day in addition to the extremes on the day in question. This and a few conventional methods are tested on the temperature time series from a European flat terrain site and from an Alpine valley site. The proposed algorithm approximates the value of the actual mean daily and monthly temperatures much better than the average of extreme temperatures. Furthermore, its bias and root mean squared error on daily and monthly timescales approach those of the algorithms that require several temperature records per day.

Natural ventilation effects on temperatures within Stevenson screens

“…This is because the daily average temperature T avg is often (Dall'Amico and Hornsteiner, 2006) calculated from the mean of the daily extremes i.e. as the 'bimean', T avg = 1 2 (T min + T max ).…”

Modelling long‐term monthly temperatures by several data‐driven methods using geographical inputs

“…Temperature is a key variable in hydrological, ecological and climate change studies that links the atmosphere and land surface processes. Several researches have been done to model air temperature (Kiraly and Janosi, ; Bartos and Janosi, ; Dall'amico and Hornsteiner, ; Holden et al , ; Evrendilek et al , ; Aznar et al , ). All these studies have emphasized the need to accurate estimation of air temperature in various aspects of meteorology, hydrology and agro‐hydrology.…”

“…Temperature is a key variable in hydrological, ecological and climate change studies that links the atmosphere and land surface processes. Several researches have been done to model air temperature (Kiraly and Janosi, 2002;Bartos and Janosi, 2006;Dall'amico and Hornsteiner, 2006;Holden et al, 2011;Evrendilek et al, 2012;Aznar et al, * Correspondence to: H. Sanikhani, Young Researchers and Elite Club, Saveh Branch, Islamic Azad University, Saveh, Iran. E-mail: hsanikhani12@gmail.com 2013).…”

A plea for more careful presentation of near‐surface air temperature data in geomorphology

“…Therefore, a series of correction or homogenization models has been developed that take the historic maximum and minimum data and transform them to make them comparable with hourly derived means (e.g., Dall'amico and Hornsteiner, 2006). This said, many temperature records are still not collected at hourly intervals and the methods for estimating the daily mean temperature have varied across the world.…”

“…if the site is revisited for a follow-up study, the study provides long-term temperature data or different instrumental records are used), then there could be mistaken inferences about climate change at the site being studied. To investigate the use of air temperature data by geomorphologists in research papers I surveyed all papers published in Earth Surface Processes and Landforms during 2004, 2005and 2006. Of the 362 papers published (including editorials and errata), 119 mentioned the word 'temperature' within the paper and 74 used temperature data (Table I).…”