Statistical analysis of solar UVB and global radiation in Kuwait

•UVB radiation, global radiation and relative humidity are measured in Shuwaikh, Kuwait for a period of two years.•Results indicate that there is a strong relationship between UVB radiation and both global and relative humidity.•Variation of diurnal UVB and global radiation with day time almost follows the same trend for measured clear days.•Cubic correlation provides best relation between UVB and global radiation as it provides highest R2 and lowest CV% values.•Highest UV index are achieved through May–August during the midday hours but never exceed extreme values (≥9).

An outdoor test facility is installed at the College of Technological Studies, Kuwait for continuous measurements of solar UVB radiation, solar global radiation, relative humidity in Kuwait for two years in the period from 1st June 2010 till 31st May 2012. It is found that the variation of diurnal UVB and global radiation with time of the day almost follows the same trend for all measured clear days. Regression analysis is adapted to establish a mathematical formula relating UVB radiation to both the global solar radiation and relative humidity. The statistical analysis of the present results revealed that there is strong relationship between UVB radiation and both global solar radiation and relative humidity, particularly in the region of moderate to low global solar radiation values. The value of UV (ultraviolet) index which is a measure of the UV radiation level at the Earth's surface is determined at different months through the day hours. The highest UV index values are achieved through the months May–August during the midday hours. However, the values of UV index never exceed the extreme value (i.e. ≥9) at any hour of the day throughout the whole period of study.