In Asia, about a billion people could face drought, land degradation and water shortage by 2050s [1] [2] . The linkages between climate change, food security and trade in South Asia are significant where the communities are mostly dependent on agriculture for both employment and subsistence [3] [4] . Pakistan is among the countries, which faces changes in temperature, where extreme weather events are creating major environment problems like drought, floods and heat waves [5] -[8] . The study of surface air temperature in complex rugged terrains caught attention of the searchers in climate sciences e.g. [9] [10] and temperature is the most important climate elements that helps in detecting climate change [11] . The monthly diagnostic of temperature variability is instrumental in future climate policy [12] [13] . For understanding the interannual changes, we need monthly temperature analysis which is also effective in intraseasonal changes, therefore, monthly temperature anomaly is considered handy tool in climate diagnostic process [14] . The anomalies more precisely elucidate climate variability over the areas than absolute temperatures do, and they give a frame of reference that allows meaningful comparison between geographical locations. The mountainous regions are more consistent in temperature variability in the contemporary warming global episode [15] [16] . The mountainous regions are more susceptible to temperature variability [17] and Himalayan region in Pakistan registered increase in temperature averages [18] . The atmospheric analogue pertaining to climate of Pakistan remained under discussion where the analysis of seasonal and annual temperatures and their trends remained under scientific discussion in Pakistan by adopting deferent approaches [19] -[23] where the rapid growing population already faces meteorological hazards. Therefore need is felt to put emphasis on ground parameterization and mapping of temperature variability. On experimental basis, the paper is focused on the spatial-temporal dynamics of temperature anomalous state of surface air temperature with emphasis on its regional characteristics in August over the decades of 1950s-2000s.

The term temperature anomaly refers to deviation from long-term averages. A positive anomaly specifies that the observed temperature is warmer than the reference value, while a negative anomaly is indicative of temperature cooler than the reference value.

The monthly ground observed temperature data from 53 stations (Figure 1) were obtained from Pakistan Meteorological Department (PMD), Government of Pakistan. The analysis is performed on decadal scale from 1950s to 2000s. In this study, total 60 months of August were taken and 10 months of each decade were analyzed separately. First, the monthly averages were calculated and the data voids were covered by interpolation. The mapped anomalies show deviations from the means of decadal temperature.

The analysis is based on the following principles,

The above equation expresses linear regression between, the time series t_i, and climate variable x_i (temperature) for the specified time period. Consider t_i as independent and x_i as dependent variable, regression coefficient “b” and the regression constant “a” of least-squares estimation have been calculated by making use of the following relations.

The linear regression coefficients were calculated for each decade. The coefficient “b” has been simulated for selected decades (Figure 1) that indicates the temperature increase or decrease with regional detail, the key bar with each figure provide guidance about the level of statistical significance.

Based on results we observed that the spatial distribution of temperature anomalies in Pakistan is quite complex and varies from place to place. The details are evident that the temperature was above average in some places while it was below average in other places. The 1950s reflects temperature above average in most parts of the country but nevertheless few regions stand exceptions like most of Balochistan. The 1960s is warmer than 1950s furthermore, the Gawadar and surrounding coastal areas were found with temperatures well above average in 1960s. The areas which are normally under the influence of summer monsoon in Pakistan configures comparatively uniform decline or rise in temperature over larger areas while the areas which are away from the summer monsoon access reflecting complex anomalous situation that vary from place to place at small scale, for example in the province of Balochistan. However, this assumption needs further intensive investigations. The 1980s seems comparatively stable than any other decade under discussion and all over the country, spatial variability of August temperature was found just close to the level of statistical significance that exhibit small temperature changes. The achieved results in 1990s were evident that this decade was obviously warmer than 1980s. The highest temperature anomalies are observed at coastal areas, Balochistan province and Indus plains in the decade of 2000s. The western parts of Indus plains, Kirthar ranges, Brahui ranges and Kharan were found above average temperature but in this scenario, the eastern parts of Indus plains, Chaghi, Noshki and Quetta valley were warmer rather. In 1960s, 1990s and 2000s, the Balochistan coastal areas reflected temperatures above the reference point.

The help and cooperation of PMD is highly acknowledged. The comments and suggestions of anonymous reviewers are highly appreciated that improved the paper.