Cambridge, United States - June 24, 2025 This summer’s first heatwave has developed across the eastern half of the United States with most places having recorded their hottest temperature of the year so far on Sunday, which will then probably be beaten on Monday and Tuesday. High pressure across the eastern US has funnelled up hot air from southern parts of the the country, resulting in what is known as a heat dome, initially across central regions on Friday, before spreading eastwards over the weekend. The temperatures rose significantly on Saturday, with Huron regional airport in South Dakota recording a high of 39.4C (102.9F), 13C above the average high in June for the region. In St Paul, Minnesota, the minimum temperature on Saturday night was 27.8C. This was 1.1C below the city’s highest night-time minimum for June, which was recorded in 1999. The heat then spread eastwards on Sunday with temperatures rising into the mid-30s widely across the plains, Midwest, mid-Atlantic and north-east. Temperatures in New York City are expected to reach 36C on Monday and Tuesday, which would set daily records, while in Washington DC, the temperature could reach 38C – matching or breaking records on both days. Boston will also experience temperatures well into the 30s Celsius, probably peaking on Tuesday with a high of 34C, just shy of daily records. Accompanying this heat will also be high levels of humidity, making it feel even hotter, with temperatures potentially feeling as high as 43C. Overall, 250 daily temperature records could be broken on Monday and Tuesday, including both record highs and record warm lows, making this heatwave particularly oppressive. SHOTLIST Haze over Cambridge, MA early on 24 June as it experiences a heatwave. [Credit: X/peterpayackpoet]