New Delhi, March 11 -- Delhi and the National Capital Region experienced an unusual mix of fog and haze on Tuesday morning, a phenomenon more typical of winter, due to moisture from a western disturbance combining with dust carried by west winds, meteorological experts said. Although fog in March is rare, the India Meteorological Department (IMD) said such episodes have occurred in the past. Visibility dropped to 600 metres at Hindon between 7am and 8am, IMD officials said. Despite the foggy start, Delhi recorded a maximum temperature of 35.5degC, around seven degrees above normal. The maximum temperature is expected to touch 37degC on Wednesday. However, a western disturbance from March 14 may lower temperatures to 32-34degC over the weekend. IMD scientist RK Jenamani said the hazy conditions were linked to increased moisture from a western disturbance affecting the western Himalayan region. "It is not very unusual as in the past too we have seen dense fog in March. This includes a March 6-8 spell in 2008, which triggered the failure of critical electrical power transmission lines across north India," Jenamani said. Mahesh Palawat, vice-president at Skymet Weather, said the haze formed as moisture trapped dust transported by westerly winds from Balochistan and the Thar Desert. Night temperatures remained high, with Delhi's minimum at 18.8degC, five degrees above normal. The dust also pushed up pollution levels, officials said. Delhi's 24-hour average air quality index (AQI) stood at 265 (poor) on Tuesday, up from 209. Ground-level ozone (O3) has emerged as a concern, typically becoming a key pollutant from late March to June. Gurugram logged a maximum temperature of 33.9degC and a minimum of 17.4degC on Tuesday, according to IMD. The district recorded a "very poor" AQI of 207, down from Monday's "poor" 257 reading....