Delhi woke up to a cloudless blue sky on Saturday due to intermittent rains over the last two days. The city and its surrounding areas also recorded the lowest concentrations of PM10, since August 18 last year. At 10 am, PM10 levels in Delhi-NCR stood at 32.5 micrograms per cubic meter, the lowest since 15.9 µg/m3 recorded on August 18 last year. The city's overall air quality index at 11 am stood at 40, which falls in the "good" category. Experts attribute the improvement to a reduction in local sources of pollution - vehicular pollution, construction dust, stack emissions etc -- due to the lockdown. Rains and gusty winds have also helped.