The United Kingdom's hottest summer ever recorded was in 2018, with an average temperature of ***** degrees Celsius. Meanwhile, 2023 saw the eighth hottest summer in the UK, with an average temperature of ***** degrees. In the last couple of decades, five of the top 10 warmest summers in the UK were recorded. New temperature records in 2022 In summer 2022, record-breaking temperatures of more than ** degrees Celsius were recorded at several locations across the UK. Accordingly, 2022 was also the UK's warmest year on record, with the average annual temperature rising above ** degrees Celsius for the first time. Since temperature recording began in ****, the hottest years documented in the country have all occurred after 2003. England: the warmest country in the UK Amongst the countries that comprise the United Kingdom, England has generally seen the highest annual mean temperatures. In 2022, England’s average temperature also reached a new record high, at nearly ** degrees Celsius. And while it’s not a typical sight in the United Kingdom, England also registered the most hours of sunshine on average, with Scotland being the gloomiest country out of the four.

The United Kingdom recorded its hottest-ever year in 2022, with an average temperature of ***** degrees Celsius. Since the start of temperature recording in ****, the ** warmest years recorded in the UK have been from 2003 onwards. Weather conditions are predicted to become more extreme due to climate change.

The average temperature in the contiguous United States reached 55.5 degrees Fahrenheit (13 degrees Celsius) in 2024, approximately 3.5 degrees Fahrenheit higher than the 20th-century average. These levels represented a record since measurements started in ****. Monthly average temperatures in the U.S. were also indicative of this trend. Temperatures and emissions are on the rise The rise in temperatures since 1975 is similar to the increase in carbon dioxide emissions in the U.S. Although CO₂ emissions in recent years were lower than when they peaked in 2007, they were still generally higher than levels recorded before 1990. Carbon dioxide is a greenhouse gas and is the main driver of climate change. Extreme weather Scientists worldwide have found links between the rise in temperatures and changing weather patterns. Extreme weather in the U.S. has resulted in natural disasters such as hurricanes and extreme heat waves becoming more likely. Economic damage caused by extreme temperatures in the U.S. has amounted to hundreds of billions of U.S. dollars over the past few decades.

'''DEFINITION''' The subsurface temperature anomaly has been derived from the regional reanalysis of the CMEMS NWS MFC group for the North-West European Shelf Seas (product reference NWSHELF_MULTIYEAR_PHY_004_009). Horizontal averaging has been conducted over just the shelf, defined as the contiguous region surrounding the UK where sea depth is no more than 200m. The profiles of the annual mean temperature anomaly have been calculated relative to the reference period of 1993-2019. The time series shows monthly anomalies calculated from monthly means. CMEMS Ocean State Report (Mulet et al., 2018) gives the broader context for these anomalies.

'''CONTEXT''' The North-West European Shelf Seas are the waters on the continental shelf adjoining the North-East Atlantic. Geographically, they can be divided into 5 regions: the North Sea, the English Channel, the Celtic Sea, the Irish Sea, and the North-Western Approaches. The temperatures in these seas is moderated by inflow from the North Atlantic Drift (a continuation of the Gulf Stream), into the Irish Sea and English Channel from the south-west and into the North Sea from the north and north-west. In Winter, this Atlantic water maintains surface temperatures no colder than 10°C in western regions. Cooler temperatures, below 3°C, can occur in eastern parts near continental coasts. In Summer, those eastern coastal regions can warm to as much as 18°C, especially in the shallow waters of the southern North Sea. Stratification occurs in the Summer months, starting around May in the northern part of the domain, and then extending southwards (Paramor et al., 2009). Currents are dominated by the strong semi-diurnal tides which act to mix the water and reduce stratification. This is especially noticeable in the shallow southern North Sea.

'''CMEMS KEY FINDINGS''' Interannual variations of the subsurface temperature anomaly averaged across the domain range from -1°C to +1°C within the upper 100-m deep layer over the period 1993-2019. There is some long-term variability, with warm anomalies for most of the first decade of the 21st century. This is a decade in which 6 of the 10 warmest years on record occurred for air temperature over the UK (Kendon et al., 2019). The 4 other warmest years for UK climate were 2011, 2014, 2017 and 2018. 2011 and 2017 correspond to warm anomalies through the depth of the Shelf. 2018 saw an unusually hot Summer heatwave for the atmosphere, which is reflected in a short-lived and shallow warm anomaly (to 25m depth) in the reanalysis. 2014 was for UK climate the hottest year on record. This corresponds to a stronger and longer-lived anomaly in the reanalysis, but only down to around 75m depth. Temperatures in deeper layers may be moderated by inflow to the region from the North Atlantic drift. 2019 was overall slightly warmer than average in near-surface layers, and slightly cooler below 100m depth.

Experimental conditions and Plant materialReplicated trials with ten wheat varieties, two irrigation regimes and two sowing dates were executed in the Lleida region, Spain, spanning the 2020–2021 (designated as the first year, 2021) and 2021–2022 (designated as the second year, 2022) growing seasons (Table 1). Trials were sown at 400 seeds m-2 rates with plot size of 8 m x 1.2 m. In the initial year, experimentation occurred in Almacelles (coordinates: 41°43′54″ N, 0°25′24″ E, elevation: 221 m), while in the subsequent year, it was conducted in Sucs (coordinates: 41°41′41″ N, 0°25′35″ E, elevation: 284 m). These sites are situated near Lleida with approximately 4 km apart and share a typical Mediterranean climate, characterized by an average annual rainfall of mm and an annual reference potential evapotranspiration of 1074 mm. In the first year, precipitation and potential evapotranspiration amounted to 364 mm and 1043 mm, respectively, whereas in the second year, they totaled 271 mm and 1105 mm, respectively, across both locations. All trials were optimally fertilized, and diseases and pests controlled with locally approved pesticides. These replicated trials were conducted using experimental micro-plots (8 m x 1.2 m). Ten distinct commercial varieties were cultivated, deliberately chosen for their contrasting phenotypic traits in phenology. All ten commercial varieties of wheat (Triticum aestivum L.) underwent evaluation under two distinct irrigation regimes: (i) 100% crop evapotranspiration (ETc), involving irrigation applied at a rate equivalent to one hundred percent of the ETc throughout the growing season, and (ii) rainfed, where no irrigation was administered. Irrigation scheduling for both years was determined using a water balance model. ETc was computed as the product of the reference potential evapotranspiration (ETo), calculated using the Penman–Monteith method [23] and the crop coefficients (Kc) approach, derived from FAO-56, and adjusted based on prevailing weather conditions before being utilized for ETc computations. Sprinklers were installed in the 100% ETc irrigation treatment at an 18 × 18 m grid spacing, with a water flow discharge rate of 7.8 L/h/m2. Irrigation was scheduled on a weekly basis using a lateral Rainger sprinkler system. Additionally, a set of 26 field trials conducted between 2018 and 2023 was used to validate the results obtained from the initial set of ten varieties, irrigation treatments, and sowing dates above. This additional set of field trials included a network of post-registration variety testing trials in Spain (https://extensius.cat/xarxes-de-varietats/) to provide farmers with annual information on the most adapted varieties of various arable crops. These trials evaluate approximately 20-38 new wheat varieties annually against established benchmark check varieties ("Artur Nick" for spring wheat and "Nogal" for winter wheat) widely cultivated in the region. The replicated trials were conducted using experimental micro-plots (8 m × 1.2 m) located in the most representative production areas across different agroclimatic zones, including Solsona, Artesa de Segre, Olius, and Lleida (Sucs). These areas are characterized by a Mediterranean climate, with hot summers and mild winters. Furthermore, a set of 22 widely grown European wheat varieties was used for validation, grown under the same conditions as the main experimental trials of ten varieties but with only one sowing date. Additionally, two collections of 147 and 158 traditional Mediterranean wheat landraces and commonly grown Mediterranean wheat varieties were used for validation. These trials followed a non-replicated augmented design with two replicated checks (cv. "Anza" and "Soissons") at a ratio of 1:4 between checks and tested genotypes, in 3.6 m² plots with eight rows spaced 0.15 m apart. All these validation trials were optimally fertilized, and diseases and pests controlled with locally approved pesticides.Agronomic traits and wheat grain quality parametersFor each variety and trial, agronomic and baking quality traits were collected and measured: days to heading (DH) as the number of days from the sowing date to when 50% of the spikes have emerged on 50% of all stems; days to maturity (DM) as the number of days from the sowing date to when 50% of the peduncles are yellow colored on 50% of all stems; grain filling duration (GF) as the number of days which occurred between DH and DM (calculated by subtracting DH from DM); grain yield (GY in ton ha-1) at 13% of humidity was determined by machine harvesting the whole plot; hectoliter weight (HLW in kg/hl) was determined by weighing a 550 ml volume of grains; thousand kernel weight (TKW in g/1000 kernels) was measured using three random samples of 200 whole grains each, with all aborted and broken grains removed; the number of grains m-2 (NG) was calculated using the grain yield (GY) and the TKW; protein content (P %) by using NIR machine (InfratecTM 1241 Grain Analyzer) using minimum 400 g of grains; sedimentation test sodium dodecyl sulphate (SDS in ml) as indicated by Pena et al. [26]. Evaluation of quality and flour rheology was carried out using Chopin alveograph following the instructions provided by the manufacturer (http://www.kpmanalytics.com/brands/chopin-technologies, accessed on 15 May 2024) to assess dough strength (W in 10-4 J), tenacity (P in mm), extensibility (L in mm) and tenacity/extensibility (P/L) ratio. Weather parameters Weather variables, such as minimum (Tmin), average (TA) and maximum (TM) temperatures (in °C, degree Celsius), precipitation (PP in mm), solar radiation (SR in MJ m-2) and potential evapotranspiration (ETo in mm) were also analyzed. Meteorological data were collected from an automated weather station located 3 km and 5 km from the Almacelles and Sucs study sites, respectively. This weather station forms part of the official Catalonian network of meteorological stations (SMC, http://www.ruralcat.net/web/guest/agrometeo, accessed on 1 August 2023). Total water availability (TOT W) was determined by adding the precipitation in millimeters to the water supplied through irrigation for irrigated trials. For rainfed trials TOT W equaled the precipitation in millimeters alone. Subsequently, averages and cumulative values were separately computed for the vegetative and grain filling stages to assess the relative exposure to these weather variables during the two different phases of plant cycle in each wheat variety. This process involved the following methods: averaged values (for temperature variables) were derived, for the vegetative stage, by dividing the sum of daily measurements from sowing to heading date by the number of days in this period (days to heading); for the grain filling stage, the sum of daily measurements from heading to maturity date was divided by the number of days in this period (grain filling duration). Cumulative values (for PP, SR, ETo and TOT W) were calculated by summing the daily measurements for each specified period. Consequently, all these newly calculated variables were designated by adding “V” for those calculated during the vegetative stage and “GF” for those calculated during the grain filling stage.

The annual mean temperature in the United Kingdom has fluctuated greatly since 1990. Temperatures during this period were at their highest in 2022, surpassing ** degrees Celsius. In 2010, the mean annual temperature stood at **** degrees, the lowest recorded during this time. Daily temperatures Average daily temperatures have remained stable since the turn of the century, rarely dropping below ** degrees Celsius. In 2010, they dropped to a low of **** degrees Celsius. The peak average daily temperature was recorded in 2022 when it reached **** degrees. This was an increase of *** degree Celsius compared to the long-term mean, and the most positive deviation during the period of consideration. Highs and lows The maximum average temperature recorded across the UK since 2015 was in July 2018. This month saw a maximum temperature of **** degrees Celsius. In comparison, the lowest monthly minimum temperature was in February of the same year, at just minus *** degrees. This was an especially cold February, as the previous year the minimum temperature for this month was *** degrees.

Detailed research has documented gradual changes to biological communities attributed to increases in global average temperatures. However, localized and abrupt temperature anomalies associated with heatwaves may cause more rapid biological changes. We analyzed temperature data from the South Island of New Zealand and investigated whether the hot summer of 2017/18 affected species of bull kelp, Durvillaeaantarctica, D. poha, and D. willana.Durvillaea spp. are large iconic seaweeds that inhabit the low intertidal zone of exposed coastlines, where they underpin biodiversity and ecosystem functioning. Sea surface temperatures (SST) during the summer of 2017/18 included the strongest marine heatwaves recorded in 38 years of existing oceanic satellite data for this region. Air temperatures were also high, and, coupled with small wave heights, resulted in strong desiccation stress during daytime low tides. Before-After analysis of drone images of four reef platforms (42, 42, 44, and 45°S) was used to evaluate changes to bull kelp over the hot summer. Bull kelp loss varied among species and reefs, with the greatest (100%) loss of D.poha at Pile Bay in Lyttelton Harbor (44°S). In Pile Bay, SST exceeded 23°C and air temperatures exceeded 30°C, while Durvillaea was exposed for up to 3 h per day during low tide. Follow-up surveys showed that all bull kelps were eliminated from Pile Bay, and from all reefs within and immediately outside of Lyttelton Harbor. Following the localized extinction of bull kelp in Pile Bay, the invasive kelp Undaria pinnatifida recruited in high densities (average of 120 m-2). We conclude that bull kelps are likely to experience additional mortalities in the future because heatwaves are predicted to increase in magnitude and durations. Losses of the endemic D. poha are particularly concerning due to its narrow distributional range.

In 2024, the average air temperature in Japan's capital reached around **** degrees Celsius. Tokyo's annual mean air temperature increased by **** degrees Celsius since 1900, showing the progress of global warming. Weather in Tokyo Tokyo lies in the humid subtropical climate zone. It is affected by the monsoon circulation and has mild, sunny winters and hot, humid, and rainy summers. In most of Japan, the rainy season lasts from early June to mid-July. Furthermore, heavy rainfall is often caused by typhoons, which develop over the Pacific Ocean and regularly approach the archipelago between July and October. In recent years, the Kanto region, including Tokyo Prefecture, was approached by at least two typhoons each year. Since the winters are rather mild in Tokyo, the capital city does not often see snowfall and the snow rarely remains on the ground for more than a few days. Effects of global warming in Japan The increasing air temperature is one of the main consequences of global warming. Other effects are increased flooding frequency and a rise in sea levels due to melting ice caps. Global warming has already influenced Japan's climate in recent years, resulting in more frequent heat waves as well as increased annual rainfall. These weather changes can intensify natural disasters such as typhoons and inhibit the growth of crops. To counter global warming, Japan aims to reduce its greenhouse gas emissions by increasing its renewable and nuclear energy share.

In 2024, the maximum average temperature in Florida stood at 83 degrees Fahrenheit. The 'sunshine' state is hardly touched by low temperatures and even sees temperatures rise above 100 degrees statewide in the summer. For many of these hot states, maximum temperatures were above normal in 2024.

The average temperature across the United Kingdom presented a trend of continuous growth since 1961. During the first period, from 1961 to 1990, the country recorded an average temperature of *** degrees Celsius. In the next period, from 1991 to 2020, the UK's average temperature increased by *** degrees Celsius and increased further by *** degrees Celsius between 2014 and 2023. In the latter year, figures remained at ** degrees Celsius, *** degrees warmer than the average recorded between 1961 and 1990, illustrating the effects of climate change. Nevertheless, 2022 was the warmest year in the United Kingdom.

In 2023, the observed annual average mean temperature in Australia reached 22.32 degrees Celsius. Overall, the annual average temperature had increased compared to the temperature reported for 1901. Impact of climate change The rising temperatures in Australia are a prime example of global climate change. As a dry country, peak temperatures and drought pose significant environmental threats to Australia, leading to water shortages and an increase in bushfires. Western and South Australia reported the highest temperatures measured in the country, with record high temperatures of over 50°C in 2022. Australia’s emission sources While Australia has pledged its commitment to the Paris Climate Agreement, it still relies economically on a few high greenhouse gas emitting sectors, such as the mining and energy sectors. Australia’s current leading source of greenhouse gas emissions is the generation of electricity, and black coal is still a dominant source for its total energy production. One of the future challenges of the country will thus be to find a balance between economic security and the mitigation of environmental impact.

Wind speed averages in the United Kingdom are generally highest in the first and fourth quarters of each calendar year – the winter months. Since 2010, the UK’s highest wind speed average was recorded in the first quarter of 2020, at 11.5 knots. During this period, 2010 was the only year that had the greatest wind speeds outside the winter months, with an average of 8.4 knots in the third quarter. In 2024, wind speeds ranged between a low of 7.9 knots in the third quarter and 9.4 knots in the first quarter. With few exceptions, UK wind speeds generally average at least eight knots annually. 2015 marked the year with the highest average wind speed in the UK (since the beginning of the reporting period in 2001), reaching an average of 9.4 knots. Wind power The UK has some of the best wind conditions in Europe for wind power. By 2023, there were 39 offshore wind farms operating across the UK, by far the most in Europe. Meanwhile, offshore wind power additions in the UK reached 1.14 gigawatts that same year. Quarterly rainfall Another weather phenomenon, UK rainfall also tends to be heaviest in the winter months. The average rainfall in the second quarter of 2024 was 254.5 millimeters, with figures in 2011 spiking to 738.6 millimeters. That year, precipitation levels in some parts of Scotland were the highest in one hundred years, while southern parts of England kept remarkably dry.