Robert Rohde

2021 was nominally the sixth warmest year since record keeping began in 1850. 25 countries, including China, Nigeria, and South Korea, set new record high annual averages.

Berkeley Earth, a California-based non-profit research organization, has been preparing independent analyses of global mean temperature changes since 2013. The following is our report on global mean temperature during 2020. We conclude that 2020 was nominally the second warmest year on Earth since 1850. Our estimate of the global mean temperature in 2020 was slightly […]

Cooling weather may have caused increased COVID-19 spread. Considered across many regions, the average reproduction number (R) gradually increased from ~1.0 to ~1.2 as daily high temperatures fell from >27 °C to ~10-15 °C (>80 °F to 50-60 °F). Other factors, including decreases in sunlight and/or UV exposure, may have slightly increased this further.

Globally, March 2022 was the 5th warmest March since record-keeping began in 1850. Due to ongoing La Niña conditions, 2022 is projected to be around the 4th or 5th warmest year overall, with only a small chance of a new record.

Globally, February 2022 was the 8th warmest February since record-keeping began in 1850. Due to ongoing La Niña conditions, 2022 is projected to be around the 4th or 5th warmest year overall, with only a small chance of a new record.

Globally, January 2022 was the 6th warmest January since record-keeping began in 1850. Due to ongoing La Niña conditions, 2022 is projected to be around the 4th or 5th warmest year overall, with only a small chance of a new record.

Globally, June 2021 was the fourth warmest June since record-keeping began in 1850. La Niña has ended, but its lasting impact has contributed to relative coolness in 2021.

Globally, March 2021 was the ninth warmest March since record-keeping began in 1850. Diminishing La Niña conditions have been present in the Pacific and contribute to the relative coolness this year.

Globally, January 2021 was the sixth warmest January since record-keeping began in 1850. Moderate La Niña conditions continue in the Pacific, making it unlikely that 2021 will set a new record for warmest year.

Globally, October 2020 was the fifth warmest October since record-keeping began in 1850. La Niña conditions strengthened in October, significantly reducing the likelihood that 2020 sets a new record for warmest year.

Globally, September 2020 is found to be the warmest September since records began in 1850. There is now a 57% chance that 2020 finishes as the warmest year on record.

Globally, July 2020 is estimated to have been tied with July 2019 as the warmest July since records began in 1850. The nominal difference between 2019 and 2020 is less than 0.01 °C, which is much smaller than the uncertainty on this temperature analysis, making 2019 and 2020 indistinguishable. Previously in 2020, we have also witnessed the warmest April, May, and June.

Globally, June 2020 is estimated to have been the warmest June since records began in 1850, exceeding the previously warmest year in 2019. However, the margin of difference between 2020 and 2019 is small compared to the estimated uncertainties. As a result June 2020 and June 2019 may be regarded as essentially tied for the warmest June. 2020 has also had both the warmest April & May.

Globally, May 2020 is estimated to have been the warmest May since records began in 1850, exceeding the previously warmest year in 2016. This follows the warmest April. Updated projections for the rest of 2020 give a 89% chance that 2020 will be a new record warm year, a significant increase relative to prior projections.

The following is a summary of global temperature conditions in Berkeley Earth’s analysis of April of 2020. April 2020 is estimated to have been the warmest April since records began in 1850. Updated projections for the rest of 2020 give a 60% chance of that 2020 will be a new record warm year. Global Summary […]

Globally, March 2020 is estimated to have been the fourth warmest March since records began in 1850. March 2020 was appreciably cooler than March 2016, and slightly cooler than March in 2017 and 2019. However, March 2020 remains warmer than all other Marchs since global temperature estimates began in 1850. This follows the 2nd warmest February and 2nd warmest January.

Warming weather is unlikely to stop the spread of the pandemic. Warm, sunny weather may have some limited impact on the rate of spread, but in the absence of strong interventions, the pandemic is likely to continue spreading through the summer months in most parts of the world.

The following is a summary of global temperature conditions in Berkeley Earth’s analysis of November 2019. Globally, November 2019 was the second warmest November since records began in 1850. The global mean temperature was 0.88 ± 0.05 °C above the 1951 to 1980 average.  This is equivalent to being 1.26 ± 0.07 °C above the 1850 to 1900 average, […]

The following is a selected list of third-party data visualizations that have used data from Berkeley Earth. Climate Data Data explorer map of past and future temperature change produced by Carbon Brief. Local changes in the number of hot days produced by The New York Times. Temperature change in major cities produced by the BBC. […]

The following is a summary of global temperature conditions in Berkeley Earth’s analysis of October 2019. Globally, October 2019 was the second warmest October since records began in 1850. The global mean temperature was 0.99 ± 0.06 °C above the 1951 to 1980 average.  This is equivalent to being 1.38 ± 0.07 °C above the 1850 to 1900 average […]

Berkeley Earth, a California-based non-profit research organization, has been preparing independent analyses of global mean temperature changes since 2013. The following is our report on global mean temperature during 2018. We conclude that 2018 was likely the fourth warmest year on Earth since 1850. Global mean temperature in 2018 was colder than 2015, 2016, and […]

Berkeley Earth, a California-based non-profit research organization, has been preparing independent analyses of global mean temperature changes since 2013. The following is our report on global mean temperature during 2017. We conclude that 2017 was likely the second warmest year on Earth since 1850. Global mean temperature in 2017 was 0.03 °C (0.05 °F) warmer […]