Carbon dioxide (CO2) observations collected at 5 min interval at Sriharikota during October 2011-January 2012 from the Vaisala GMP-343 sensor were averaged on an hourly basis. The baseline of atmospheric CO2 during study period is 382 ppm. Minimum (maximum) mixing ratios was observed during the afternoon (night times) indicating the role of photosynthetic activity and the atmospheric boundary on this parameter. Sriharikota being a coastal station, the land and sea breezes mainly control CO2 mixing ratios. The correlation between CO2 and the wind speed is significantly less during sea breeze than during land breeze in October, compared to other months, where the correlations are more during sea breeze. The less correlation during sea breeze in October is due to the heavy rainfall in this month during daytime.