The continental United States sweated through its hottest July on record, US weather officials say. The National Oceanic and Atmospheric Administration (NOAA) said the average temperature was 25.3C, which was 1.8 degrees warmer than the average in the 20th century. \"The warm July temperatures contributed to a record-warm first seven months of the year and the warmest 12-month period the nation has experienced since record keeping began in 1895,\" NOAA said. Ongoing drought has expanded to cover nearly 63 per cent of the lower 48 states. Wildfires have consumed 800,000 hectares of foliage this year so far, nearly 200,000 hectares above average, NOAA said.