Stable high pressure conditions continued to dominate the weather in the Mackenzie Delta. No low clouds were present and temperatures raised up to 20°C. These situation was suited for a second clear sky flight. As it was not clear sky at all, with a thick cirrus field above the area, Polar 5 did stay on ground this day having no chance for reasonable good measurements. Polar 6 instead repeated the flight pattern from May 11 profiling the atmosphere at two locations with a ''curtain'' of horizontal legs in different altitudes.

The first profile was flown somewhat further north compared to the last flight above sea ice while the second profile again was located close to Tuk. As forecasted, in the measurement area Polar 6 encountered now low clouds reachable for in situ measurements. However, there was a closed unstructured, diffuse cloud deck (low altostratus) around 20000 ft altitude, probably with 8/8 coverage present throughout the entire flight. It was optically fairly thick although the sun could be seen through at times. On the way to the first profile Polar 6 flew inside a haze layer at 10000 ft, probably the lower end of the cloud deck above. Outbound North the approaching frontal system can be seen to the West like a cloud wall. The cloud particle instruments report 5 μm droplets from the haze we are flying in. During the profiling with legs lat 10000 ft, 8000 ft, 6000 ft, 4000 ft, 3000 ft, 2000 ft, 1500 ft, 1000 ft and 500 ft, different haze layers were observable. In general higher aerosol concentrations were found compared to May 11. The highest concentrations were not measured at ground level but in the higher legs of the profile.