Abstract : Temperature records showed differences in the magnitude between urban and suburban, which usually urban areas show greater magnitudes than rural areas. The variance in temperature is called Urban Heat Island phenomena. In this study, small area respective to population rate was chosen as a case study to seek the impact of measuring times on UHI in Saif Saad district - Karbala city /Iraq. Study methodology is selecting three points at both urban and suburban areas to show the impact of two measuring times: one at the midday and the other is immediately after sunset. This study mentioned that there is a fluctuated in air temperature at 1.5 m above the ground at daytime but there is a stable temperature at night time. Respective to UHIs magnitude, there is significant values of urban heat island at both urban and suburban areas with both measuring times on day and night times. Generally, urban area is warmer than suburban area by increasing temperature value of 2.38oC. Study conclusions are air temperature magnitudes at small urban area are always greater than suburban area along winter season. Also, small areas likely quarters have severed from Urban Heat Island phenomena, which could because UHI values were observed at both daytimes and night times. Measuring times close to the midday hour and just after the sunset appear the precise values of UHI. Therefore, city planner and designers should put these times within scheduling measuring times to record temperature at urban and suburban areas.