Overview
This report examines air and sea surface temperature data from 1960 through the most recently completed quarter, providing estimates of both recent and long-term warming trends. This quarterly update extends the analysis through June 2026.
Key Findings
- Estimated warming rates have increased across time, consistent with an acceleration in global warming. For the most recent 30-year period, the estimated trend in global air temperature is approximately 0.48°F per decade.
- Trends vary significantly by region: the northern hemisphere is warming at a faster rate than the southern hemisphere, and land areas are warming faster than the surface of the sea.
- After reaching record-high levels in 2023 and 2024, in 2025 both global air temperature and sea surface temperature (SST) eased slightly from their peaks.
- The slight easing observed in 2025 halted in early 2026, and global temperature is once again climbing towards record levels. This is particularly evident for SST, which reached a new seasonally-adjusted record high in June 2026.
Air and Sea Surface Temperature Anomalies (°F), 1961 to 2026
Average Air Temperature Anomaly (°F) from July 2025 to June 2026
Temperature Trends Estimated Using Linear Regression Across 30-Year Periods
FAQs
All results are based on the ERA5 reanalysis dataset produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). As stated on the ECMWF website, “reanalysis data provide the most complete picture currently possible of past weather and climate. They are a blend of observations with past short-range weather forecasts rerun with modern weather forecasting models. They are globally complete and consistent in time and are sometimes referred to as ‘maps without gaps’.”
ERA5 provides data for Earth’s entire surface, at intervals of 0.5 degrees latitude and longitude. ERA5 grid points are evenly spaced with respect to degrees of latitude and longitude, but they are not evenly spaced when measured in miles or kilometers. As one approaches the poles, lines of longitude converge, reducing the distance between grid points. Consequently, an unweighted global average across grid points would result in the overweighting of data near the North and South Poles.
The standard remedy used by climate scientists—and the approach used for the analysis presented in this report—is to weight each data point by the cosine of its latitude. At the equator, the resulting weight is 1.0; at 45 degrees north or south, the weight is approximately 0.71; at 60 degrees north or south, the weight is 0.50, declining toward zero as latitude approaches either pole. This decline counterbalances the increasing density of grid points at high latitudes, resulting in an even spatial weighting across the surface of the Earth.