Global temperatures were exceptionally high in 2023/24. Every month from June 2023 to June 2024 set a new record, and September shattered the previous record by $0.5$°C. The 2023 annual average approached $1.5$°C above pre-industrial levels. This results from both long-term warming and internal variability, with the occurrence of an El Niño episode. However the amplitude of the 2023/24 anomalies was remarkable and surprised the scientific community. Here we analyze the rarity of 2023/24 global temperatures from a climate perspective. We show that a ‘normal’ year 2023 would have roughly equaled the previous annual record, and that the most extreme events of 2023/24 rank among the most extreme since 1940. Our analysis suggests that the 2023/24 event can be reconciled with the long-term trend and an intense, but not implausible, peak of internal variability.

中文翻译：

---

2023 年和 2024 年初全球每日气温有多极端？


2023/24 年全球气温异常高。从 2023 年 6 月到 2024 年 6 月，每个月都创下新纪录，9 月打破了之前的记录 $0.5$°C。 2023 年的年平均值接近比工业化前水平高 $1.5$。这是长期变暖和内部变率的结果，厄尔尼诺现象的发生。然而，2023/24 年异常的幅度是显着的，让科学界感到惊讶。在这里，我们从气候角度分析了 2023/24 年全球气温的稀有性。我们表明，2023 年的“正常”年份将大致等于之前的年度记录，而 2023/24 年最极端的事件是自 1940 年以来最极端的事件之一。我们的分析表明，2023/24 年事件可以与长期趋势和强烈但并非不可信的内部变率峰值相协调。