July is on track to be the hottest month on record, according to the World Meteorological Organization which looked at data from the EU-funded Copernicus Climate Change Service (C3S). The first three weeks of July have already been the hottest ever recorded and the WMO says these temperatures have been related to heatwaves in large parts of North America, Asia and Europe, which along with wildfires in countries including Canada and Greece, have had major impacts on people’s health, the environment and economies. On July 6, the daily average global mean surface air temperature surpassed the record set in August 2016, making it the hottest day on record, with July 5 and July 7 shortly behind.
Organisation/s: World Meteorological Organization (WMO)
Funder: UN
Media release
From: World Meteorological Organization (WMO)
Copernicus and WMO: July 2023 is set to be the hottest month on record
Bonn and Geneva, 27/07/2023
According to ERA5 data from the EU-funded Copernicus Climate Change Service (C3S), the first three weeks of July have been the warmest three-week period on record and the month is on track to be the hottest July and the hottest month on record. These temperatures have been related to heatwaves in large parts of North America, Asia and Europe, which along with wildfires in countries including Canada and Greece, have had major impacts on people’s health, the environment and economies.
On July 6, the daily average global mean surface air temperature surpassed the record set in August 2016, making it the hottest day on record, with July 5 and July 7 shortly behind. The first three weeks of July have been the warmest three-week period on record. Global mean temperature temporarily exceeded the 1.5° Celsius threshold above preindustrial level during the first and third week of the month (within observational error). Since May, the global average sea surface temperature* has been well above previously observed values for the time of the year; contributing to the exceptionally warm July.
It is extremely likely that July 2023 will be the hottest July and also the hottest month on record, following on from the hottest June on record. According to ERA5 data the previous hottest July and month on record was July 2019. Complete ERA5 data for July will be available and published by C3S in their upcoming monthly bulletin on August 8.
Carlo Buontempo, Director of the Copernicus Climate Change Service (C3S) at ECMWF, comments: “Record-breaking temperatures are part of the trend of drastic increases in global temperatures. Anthropogenic emissions are ultimately the main driver of these rising temperatures”. He added “July’s record is unlikely to remain isolated this year, C3S’ seasonal forecasts indicate that over land areas temperatures are likely to be well above average, exceeding the 80th percentile of climatology for the time of year”.
“The extreme weather which has affected many millions of people in July is unfortunately the harsh reality of climate change and a foretaste of the future,” said World Meteorological Organization’s Secretary-General Prof. Petteri Taalas. “The need to reduce greenhouse gas emissions is more urgent than ever before. Climate action is not a luxury but a must.”
WMO predicts that there is a 98% likelihood that at least one of the next five years will be the warmest on record and a 66% chance of temporarily exceeding 1.5°C above the 1850-1900 average for at least one of the five years.
This does not mean that we will permanently exceed the 1.5°C level specified in the Paris Agreement which refers to long-term warming over many years.
C3S, implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) on behalf of the European Commission, routinely monitors climate and has also been closely following recent development of global air and sea surface temperatures.
The World Meteorological Organization (WMO) consolidates data from C3S and five other international datasets for its climate monitoring activities and its State of the Climate reports.
FACTS AND FIGURE
Highest daily global mean surface air temperatures on record
Figure S1. Ranking of the top 30 warmest days in the ERA5 dataset based on globally averaged surface air temperature. Days in July 2023 are highlighted in bold. Data: ERA5. Credit: C3S/ECMWF.
According to the ERA5 dataset, the global mean surface air temperature reached its highest daily value (17.08°C) on 6th July 2023. This value was within 0.01°C of the values recorded on 5th and 7th July. As shown in the chart above, all days since 3rd July have been hotter than the previous record of 16.80°C from 13th August 2016.
Highest monthly global mean surface air temperature on record
Figure S2. Ranking of the top 30 warmest months in the ERA5 dataset based on globally averaged surface air temperature. The average temperature for July is based on data for the first 23 days of the month. Data: ERA5. Credit: C3S/ECMWF.
According to the ERA5 dataset, the global mean surface air temperature averaged for the first 23 days of July 2023 was 16.95°C. This is well above the 16.63°C recorded for the full month of July 2019, which is currently the warmest July and warmest month on record. At this stage, it is virtually certain that the full monthly average temperature for July 2023 will exceed that of July 2019 by a significant margin, making July 2023 the warmest July and warmest month on record.
Note that the current ranking for the warmest July from NOAA based on the NOAAGlobalTemp dataset differs from the ranking based on ERA5. NOAA puts July 2021 as the warmest July whereas it is July 2019 in ERA5 (ERA5 ranks July 2021 as the 4th warmest). This difference in rankings can be explained by differences in spatial coverage between the two datasets. While ERA5 provides temperature estimates over the entire globe, vast portions of the polar regions are not covered by NOAA’s dataset, as can be seen in this figure.
Hottest three weeks on record
Figure S3. Globally averaged surface air temperature for the first 23 days of July for all months of July from 1940 to 2023. Twenty-three days represent the number of days in July 2023 for which ERA5 data are available as of writing of this document. Data: ERA5. Credit: C3S/ECMWF.
The fact that the first 3 weeks of July (3rd to 23rd July) have been the 3 hottest weeks on record can be inferred from the chart of daily temperature time series included in the main body of the statement as well as from Figure S1 (the 21 days since 3rd July are the hottest 21 days in the ERA5 dataset). Furthermore, if we compare the average temperature for the first 23 days of July 2023 (for which we have data from ERA5) with the same average for all months of July going back to 1940, July 2023 clearly stands out as the warmest month on record, as shown in Figure S3.
Global mean temperature temporarily exceeded the 1.5°C threshold
The 1.5°C warming threshold above preindustrial level (1850–1900) is shown in the figure used in the main body of the statement. In this figure, the dashed line represents the best estimate of the threshold while the grey envelope represents the uncertainty range around this estimate. The methodology used to produce daily estimates of the 1.5°C threshold and its uncertainty is outlined in a C3S article and a C3S About the data and analysis webpage.
According to ERA5 data, the daily global mean surface air temperature temporarily surpassed the best-estimate line once from 3rd to 12th July and then again from 17th to 22nd July. While the threshold had been previously exceeded in other months (most notably during winter 2015-2016 and spring 2016), this was the first time the threshold was exceeded in July. This was also the case in early June 2023 (as reported by C3S) when the daily global temperature rose above the threshold for the first time during that month (as reported in a C3S article).
Well above-average global sea surface temperatures
Figure S4. Daily global sea surface temperature (°C) averaged over the 60°S–60°N domain plotted as time series for each year from 1 January 1979 to 23 July 2023. The years 2023 and 2016 are shown with thick lines shaded in bright red and dark red, respectively. Other years are shown with thin lines and shaded according to the decade, from blue (1970s) to brick red (2020s). Data: ERA5. Credit: C3S/ECMWF.
Daily sea surface temperatures (SSTs) averaged over the global extrapolar oceans (60°S–60°N) have stayed at record values for the time of year since April 2023. Most notably, since about mid-May, global SSTs have risen to unprecedented levels for the time of year. According to ERA5 data, on 19th July, the daily SST value reached 20.94°C, only 0.01°C shy of the highest value recorded for 29th March 2016 (20.95°C).
New national temperature records
National meteorological and hydrological services have reported a number of daily and station temperature records and are responsible for verifying any new national temperature records. Thus, China set a new national temperature record of 52.2°C on 16 July (Turpan city in China’s Xinjiang province), according to the China Meteorological Administration. WMO’s provisional State of the Global Climate 2023 report, which will be presented to COP28 in December, will incorporate details of new national temperature records.
The temperature record for continental Europe of 48.8°C (119.8°F) measured in Sicily on 11 August 2021 was not broken during the July heatwaves, according to provisional information.
Temperature records in the United States of America are maintained by the US National Oceanic and Atmospheric Administration’s National Centers for Environmental Information.
C3S, implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) on behalf of the European Commission, routinely monitors climate and has also been closely following recent development of global air and sea surface temperatures.
The World Meteorological Organization (WMO) consolidates data from C3S and five other international datasets for its climate monitoring activities and its State of the Climate reports.
For further information on the high temperatures in early July, you can read this article, once the embargo is lifted.
You can find C3S seasonal forecast here.
Answers to frequently asked questions regarding temperature monitoring can be found here.
Information about the C3S data set and how it is compiled.
Temperature maps and data are from ECMWF Copernicus Climate Change Service’s ERA5 dataset.
*The global Sea Surface Temperature (SST) is measure for 60S-60N, as this is the domain commonly used to estimate this indicator as it represents (to a large extent) the ocean domain free of sea ice where SST can be estimated from satellite observations.
More information on the reference period used, can be found here.
About Copernicus and ECMWF
Copernicus is the Earth observation component of the European Union’s space programme, implemented with funding from the EU, which operates six thematic services: Atmosphere, Marine, Land, Climate Change, Security and Emergency. It delivers freely accessible operational data and services, providing users with reliable and up-to-date information related to our planet and its environment. Copernicus is coordinated and managed by the European Commission and implemented in partnership with the Member States, the European Space Agency (ESA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the European Centre for Medium-Range Weather Forecasts (ECMWF), EU Agencies and Mercator Océan, amongst others.
ECMWF operates two services from the EU’s Copernicus Earth observation component: the Copernicus Atmosphere Monitoring Service (CAMS) and the Copernicus Climate Change Service (C3S). They also contribute to the Copernicus Emergency Management Service (CEMS), which is implemented by the EU Joint Research Centre (JRC). The European Centre for Medium-Range Weather Forecasts (ECMWF) is an independent intergovernmental organisation supported by 35 states. It is both a research institute and a 24/7 operational service, producing and disseminating numerical weather predictions to its Member States. This data is fully available to the national meteorological services in the Member States. The supercomputer facility (and associated data archive) at ECMWF is one of the largest of its type in Europe and Member States can use 25% of its capacity for their own purposes.
ECMWF has expanded its location across its Member States for some activities. In addition to an HQ in the UK and Computing Centre in Italy, offices with a focus on activities conducted in partnership with the EU, such as Copernicus, are in Bonn, Germany.
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Expert Reaction
These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.
Dr Andrew King is a Senior Lecturer in Climate Science at the School of Geography, Earth and Atmospheric Sciences, University of Melbourne and the ARC Centre of Excellence for Climate Extremes (CLEx)
“In the last few months, we’ve seen a seemingly endless series of extreme weather events in the Northern Hemisphere. The extreme heat in parts of the US and Mexico, Southern Europe and China has smashed high-temperature records while parts of the Northeastern US, Central Europe and South Korea have seen dramatic and devastating extreme rain and floods.
Given the simultaneous heatwaves across large areas of the Northern Hemisphere, it’s no surprise that July is almost guaranteed to be the planet’s hottest month on record. We know that this global heat record would have been virtually impossible without the effect of humanity’s greenhouse gas emissions.
As a probable El Niño develops, Australians should be prepared for a hotter and drier summer than we’ve seen the last three summers. An El Niño increases the chance of major heatwaves and weather conducive to fire spread across the north and east of the continent. “
Last updated: 28 Jul 2023 11:14am
Declared conflicts of interest:
None declared.