High impact weather events such as extreme temperatures or rainfall can cause significant disruption across the UK affecting sectors such as health, transport, agriculture and energy. In this study we draw on the latest set of UK climate projections, UKCP, to examine metrics relating to high-impact weather over the UK and how these change with different levels of future global warming from 1.5 °C to 4 °C above pre-industrial. The changes to these hazards show increases in the frequency of extremely hot days and nights, with a UK average increase in hot days of between 5 and 39 days per year between 1.5 °C and 4 °C of global warming. Projections indicate an increase in cooling degree days of 134–627% and an increase in growing degree days of 19–60% between 1.5 °C and 4 °C of global warming. Extremely hot nights, which are currently rare, are emerging as more common occurrences. The frequency of high daily temperatures and rainfall increase systematically, while the frequency of very cold conditions (based on days where temperatures fall below 0 °C) is shown to decrease by 10 to 49 days per year. A reduction in heating degree days, of 11–32% between 1.5 °C and 4 °C of warming, is projected. Levels of daily rainfall, which currently relate to increased risk of river flooding, are shown to increase across the country, with increases of days with high impact levels of rainfall occurring by 1 to 8 days per year between 1.5 °C and 4 °C of warming. Average drought severity is projected to increase for 3-, 6-, 12- and 36-month-long droughts. The largest changes in the severity of the 12-month drought are between −3 and +19% between 1.5 °C and 4 °C of warming and for 36-month drought between −2 and +54% between 1.5 °C and 4 °C of warming. The projected future changes in high impact weather from this study will enable the characterization of climate risks and ultimately be able to better inform adaptation planning in different sectors to support the increase in resilience of the UK to future climate variability and change.

极端温度或降雨等高影响天气事件可能在英国造成重大破坏，影响健康、运输、农业和能源等部门。在这项研究中，我们利用最新的英国气候预测集 UKCP 来研究与英国高影响天气相关的指标，以及这些指标如何随着未来全球变暖从 1.5°C 升高到 4°C 的不同水平而发生变化。工业的。这些危害的变化表明，极端炎热的昼夜频率增加，英国每年平均炎热天数增加 5 至 39 天，全球变暖 1.5°C 至 4°C。预测表明，在全球变暖 1.5 °C 和 4 °C 之间，冷却度日数增加 134-627%，生长期日数增加 19-60%。极热的夜晚，目前很少见，正在成为更常见的事件。每日高温和降雨的频率系统性地增加，而极冷条件（基于温度低于 0 °C 的天数）的频率显示为每年减少 10 至 49 天。预计升温 1.5°C 至 4°C 之间的采暖度日数将减少 11-32%。目前与河流洪水风险增加有关的每日降雨量在全国范围内都在增加，每年在 1.5°C 到 4°C 之间发生 1 到 8 天的高影响降雨量的天数增加。变暖。预计 3、6、12 和 36 个月的干旱的平均干旱严重程度将增加。12 个月干旱严重程度的最大变化介于 -3 和 +19% 之间，介于 1 之间。5 °C 和 4 °C 的变暖以及 36 个月的干旱，介于 -2 和 +54% 之间，介于 1.5 °C 和 4 °C 之间。本研究预测的高影响天气未来变化将使气候风险的特征成为可能，并最终能够更好地为不同部门的适应规划提供信息，以支持英国提高对未来气候变率和变化的适应能力。